diff --git a/jira/client.py b/jira/client.py
index b23aff2de..a983e1f3d 100644
--- a/jira/client.py
+++ b/jira/client.py
@@ -32,8 +32,10 @@
     Callable,
     Generic,
     Literal,
+    ParamSpec,
     SupportsIndex,
     TypeVar,
+    cast,
     no_type_check,
     overload,
 )
@@ -100,7 +102,7 @@
 try:
     from requests_jwt import JWTAuth
 except ImportError:
-    pass
+    JWTAuth = None
 
 
 LOG = _logging.getLogger("jira")
@@ -183,7 +185,11 @@ def is_experimental(*args, **kwargs):
     return is_experimental
 
 
-def translate_resource_args(func: Callable):
+P = ParamSpec("P")
+R = TypeVar("R")
+
+
+def translate_resource_args(func: Callable[P, R]) -> Callable[P, R]:
     """Decorator that converts Issue and Project resources to their keys when used as arguments.
 
     Args:
@@ -191,8 +197,8 @@ def translate_resource_args(func: Callable):
     """
 
     @wraps(func)
-    def wrapper(*args: Any, **kwargs: Any) -> Any:
-        arg_list = []
+    def wrapper(*args: P.args, **kwargs: P.kwargs) -> R:
+        arg_list: list[Any] = []
         for arg in args:
             if isinstance(arg, Issue | Project):
                 arg_list.append(arg.key)
@@ -200,8 +206,7 @@ def wrapper(*args: Any, **kwargs: Any) -> Any:
                 arg_list.append(arg.name)
             else:
                 arg_list.append(arg)
-        result = func(*arg_list, **kwargs)
-        return result
+        return cast(Callable[..., R], func)(*arg_list, **kwargs)
 
     return wrapper
 
@@ -214,13 +219,13 @@ def _field_worker(
     return {"fields": fieldargs}
 
 
-ResourceType = TypeVar("ResourceType", contravariant=True, bound=Resource)
+ResourceType = TypeVar("ResourceType", bound=Resource)
 
 
-class ResultList(list, Generic[ResourceType]):
+class ResultList(list[ResourceType], Generic[ResourceType]):
     def __init__(
         self,
-        iterable: Iterable | None = None,
+        iterable: Iterable[ResourceType] | None = None,
         _startAt: int = 0,
         _maxResults: int = 0,
         _total: int | None = None,
@@ -306,8 +311,7 @@ def _generate_qsh(self, req):
         return qsh
 
     def _sort_and_quote_values(self, values):
-        ordered_values = sorted(values)
-        return [quote(value, safe="~") for value in ordered_values]
+        return [quote(value, safe="~") for value in sorted(values)]
 
 
 class JiraCookieAuth(AuthBase):
@@ -464,6 +468,8 @@ class JIRA:
     JIRA_BASE_URL = Resource.JIRA_BASE_URL
     AGILE_BASE_URL = AgileResource.AGILE_BASE_URL
 
+    _session_obj: ResilientSession | None
+
     def __init__(
         self,
         server: str | None = None,
@@ -611,21 +617,21 @@ def __init__(
         assert isinstance(self._options["headers"], dict)  # for mypy benefit
 
         # Create Session object and update with config options first
-        self._session = ResilientSession(timeout=timeout)
+        self._session_obj = ResilientSession(timeout=timeout)
         # Add the client authentication certificate to the request if configured
         self._add_client_cert_to_session()
         # Add the SSL Cert to the request if configured
         self._add_ssl_cert_verif_strategy_to_session()
 
-        self._session.headers.update(self._options["headers"])
+        self._session_obj.headers.update(self._options["headers"])
 
         if "cookies" in self._options:
-            self._session.cookies.update(self._options["cookies"])
+            self._session_obj.cookies.update(self._options["cookies"])
 
-        self._session.max_retries = max_retries
+        self._session_obj.max_retries = max_retries
 
         if proxies:
-            self._session.proxies = proxies
+            self._session_obj.proxies = proxies
 
         # Setup the Auth last,
         # so that if any handlers take a copy of the session obj it will be ready
@@ -737,17 +743,15 @@ def __del__(self):
         self.close()
 
     def close(self):
-        session = getattr(self, "_session", None)
-        if session is not None:
+        if self._session_obj:
             try:
-                session.close()
+                self._session_obj.close()
             except TypeError:
                 # TypeError: "'NoneType' object is not callable" could still happen here
                 # because other references are also in the process to be torn down,
                 # see warning section in https://docs.python.org/2/reference/datamodel.html#object.__del__
                 pass
-            # TODO: https://github.com/pycontribs/jira/issues/1881
-            self._session = None  # type: ignore[arg-type,assignment]
+            self._session_obj = None
 
     def _check_for_html_error(self, content: str):
         # Jira has the bad habit of returning errors in pages with 200 and embedding the
@@ -809,6 +813,7 @@ def json_params() -> dict[str, Any]:
 
         page_params = json_params()
 
+        batch_size = None
         if startAt:
             page_params["startAt"] = startAt
         if maxResults:
@@ -909,7 +914,7 @@ def json_params() -> dict[str, Any]:
         else:  # TODO: unreachable
             # it seems that search_users can return a list() containing a single user!
             return ResultList(
-                [item_type(self._options, self._session, resource)], 0, 1, 1, True
+                [item_type(self._options, self._session_obj, resource)], 0, 1, 1, True
             )
 
     @cloud_api
@@ -1060,6 +1065,12 @@ def application_properties(
             params["key"] = key
         return self._get_json("application-properties", params=params)
 
+    @property
+    def _session(self) -> ResilientSession:
+        if self._session_obj is None:
+            raise JIRAError("JIRA instance has been closed and can no longer be used.")
+        return self._session_obj
+
     def set_application_property(self, key: str, value: str):
         """Set the application property.
 
@@ -2552,8 +2563,7 @@ def add_remote_link(
         url = self._get_url("issue/" + str(issue) + "/remotelink")
         r = self._session.post(url, data=json.dumps(data))
 
-        remote_link = RemoteLink(self._options, self._session, raw=json_loads(r))
-        return remote_link
+        return RemoteLink(self._options, self._session, raw=json_loads(r))
 
     def add_simple_link(self, issue: str, object: dict[str, Any]):
         """Add a simple remote link from an issue to web resource.
@@ -2577,8 +2587,7 @@ def add_simple_link(self, issue: str, object: dict[str, Any]):
         url = self._get_url("issue/" + str(issue) + "/remotelink")
         r = self._session.post(url, data=json.dumps(data))
 
-        simple_link = RemoteLink(self._options, self._session, raw=json_loads(r))
-        return simple_link
+        return RemoteLink(self._options, self._session, raw=json_loads(r))
 
     # non-resource
     @translate_resource_args
@@ -4006,10 +4015,8 @@ def search_assignable_users_for_issues(
                 "Either 'username' or 'query' arguments must be specified."
             )
 
-        if username is not None:
-            params = {"username": username}
-        if query is not None:
-            params = {"query": query}
+        params: dict[str, Any] = {"query": query} if query else {"username": username}
+
         if project is not None:
             params["project"] = project
         if issueKey is not None:
@@ -4170,7 +4177,8 @@ def delete_remote_link(
 
         if internal_id is not None:
             url = self._get_url(f"issue/{issue}/remotelink/{internal_id}")
-        elif global_id is not None:
+        else:
+            assert global_id is not None
             # stop "&" and other special characters in global_id from messing around with the query
             global_id = urllib.parse.quote(global_id, safe="")
             url = self._get_url(f"issue/{issue}/remotelink?globalId={global_id}")
@@ -4495,11 +4503,10 @@ def _timestamp(dt: datetime.timedelta | None = None):
         return calendar.timegm(t.timetuple())
 
     def _create_jwt_session(self, jwt: dict[str, Any]):
-        try:
-            jwt_auth = JWTAuth(jwt["secret"], alg="HS256")
-        except NameError as e:
-            self.log.error("JWT authentication requires requests_jwt")
-            raise e
+        if JWTAuth is None:
+            raise JIRAError("JWT authentication requires requests_jwt")
+
+        jwt_auth = JWTAuth(jwt["secret"], alg="HS256")
         jwt_auth.set_header_format("JWT %s")
 
         jwt_auth.add_field("iat", lambda req: JIRA._timestamp())
@@ -5505,7 +5512,7 @@ def boards(
     @translate_resource_args
     def sprints(
         self,
-        board_id: int,
+        board_id: int | str,
         extended: bool | None = None,
         startAt: int = 0,
         maxResults: int = 50,
@@ -5543,7 +5550,7 @@ def sprints(
 
     def sprints_by_name(
         self, id: str | int, extended: bool = False, state: str | None = None
-    ) -> dict[str, dict[str, Any]]:
+    ) -> dict[str, dict[str, Any] | None]:
         """Get a dictionary of sprint Resources where the name of the sprint is the key.
 
         Args:
@@ -5651,6 +5658,7 @@ def sprint_info(self, board_id: str, sprint_id: str) -> dict[str, Any]:
         """
         sprint = Sprint(self._options, self._session)
         sprint.find(sprint_id)
+        assert sprint.raw is not None, "sprint.raw is None but should be set by sprint.find()"
         return sprint.raw
 
     def sprint(self, id: int) -> Sprint:
@@ -5836,7 +5844,8 @@ def rank(
         if next_issue is not None:
             before_or_after = "Before"
             other_issue = next_issue
-        elif prev_issue is not None:
+        else:
+            assert prev_issue is not None
             before_or_after = "After"
             other_issue = prev_issue
 
diff --git a/jira/resources.py b/jira/resources.py
index 7127e2402..1d28db796 100644
--- a/jira/resources.py
+++ b/jira/resources.py
@@ -15,7 +15,9 @@
 
 from requests import Response
 from requests.structures import CaseInsensitiveDict
+from typing_extensions import override
 
+from jira.exceptions import JIRAError
 from jira.resilientsession import ResilientSession, parse_errors
 from jira.utils import json_loads, remove_empty_attributes, threaded_requests
 
@@ -129,7 +131,7 @@ class Resource:
     def __init__(
         self,
         resource: str,
-        options: dict[str, Any],
+        options: dict[str, Any] | None,
         session: ResilientSession,
         base_url: str = JIRA_BASE_URL,
     ):
@@ -143,6 +145,8 @@ def __init__(
 
         """
         self._resource = resource
+        if options is None:
+            options = {}
         self._options = options
         self._session = session
         self._base_url = base_url
@@ -508,10 +512,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "attachment/{0}", options, session)
+        super().__init__("attachment/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def get(self):
         """Return the file content as a string."""
@@ -533,10 +536,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "component/{0}", options, session)
+        super().__init__("component/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def delete(self, moveIssuesTo: str | None = None):  # type: ignore[override]
         """Delete this component from the server.
@@ -560,10 +562,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "customFieldOption/{0}", options, session)
+        super().__init__("customFieldOption/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Dashboard(Resource):
@@ -575,11 +576,10 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "dashboard/{0}", options, session)
+        super().__init__("dashboard/{0}", options, session)
         if raw:
             self._parse_raw(raw)
         self.gadgets: list[DashboardGadget] = []
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class DashboardItemPropertyKey(Resource):
@@ -591,10 +591,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "dashboard/{0}/items/{1}/properties", options, session)
+        super().__init__("dashboard/{0}/items/{1}/properties", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class DashboardItemProperty(Resource):
@@ -611,7 +610,6 @@ def __init__(
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def update(  # type: ignore[override] # incompatible supertype ignored
         self, dashboard_id: str, item_id: str, value: dict[str, Any]
@@ -633,6 +631,8 @@ def update(  # type: ignore[override] # incompatible supertype ignored
         options["path"] = (
             f"dashboard/{dashboard_id}/items/{item_id}/properties/{self.key}"
         )
+        if not self.raw:
+            self.raw = {"value": {}}
         self.raw["value"].update(value)
         self._session.put(self.JIRA_BASE_URL.format(**options), self.raw["value"])
 
@@ -666,11 +666,10 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "dashboard/{0}/gadget/{1}", options, session)
+        super().__init__("dashboard/{0}/gadget/{1}", options, session)
         if raw:
             self._parse_raw(raw)
         self.item_properties: list[DashboardItemProperty] = []
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def update(  # type: ignore[override] # incompatible supertype ignored
         self,
@@ -742,10 +741,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "field/{0}", options, session)
+        super().__init__("field/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Filter(Resource):
@@ -757,10 +755,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "filter/{0}", options, session)
+        super().__init__("filter/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Issue(Resource):
@@ -805,14 +802,13 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}", options, session)
+        super().__init__("issue/{0}", options, session)
 
         self.fields: Issue._IssueFields
         self.id: str
         self.key: str
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def update(  # type: ignore[override] # incompatible supertype ignored
         self,
@@ -930,10 +926,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/comment/{1}", options, session)
+        super().__init__("issue/{0}/comment/{1}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def update(  # type: ignore[override]
         # The above ignore is added because we've added new parameters and order of
@@ -986,10 +981,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/pinned-comments", options, session)
+        super().__init__("issue/{0}/pinned-comments", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class RemoteLink(Resource):
@@ -1001,10 +995,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/remotelink/{1}", options, session)
+        super().__init__("issue/{0}/remotelink/{1}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def update(  # type: ignore[override]
         self,
@@ -1045,20 +1038,18 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/votes", options, session)
+        super().__init__("issue/{0}/votes", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class IssueTypeScheme(Resource):
     """An issue type scheme."""
 
     def __init__(self, options, session, raw=None):
-        Resource.__init__(self, "issuetypescheme", options, session)
+        super().__init__("issuetypescheme", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class IssueSecurityLevelScheme(Resource):
@@ -1070,7 +1061,6 @@ def __init__(self, options, session, raw=None):
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class NotificationScheme(Resource):
@@ -1082,7 +1072,6 @@ def __init__(self, options, session, raw=None):
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class PermissionScheme(Resource):
@@ -1094,7 +1083,6 @@ def __init__(self, options, session, raw=None):
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class PriorityScheme(Resource):
@@ -1106,7 +1094,6 @@ def __init__(self, options, session, raw=None):
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class WorkflowScheme(Resource):
@@ -1118,7 +1105,6 @@ def __init__(self, options, session, raw=None):
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Watchers(Resource):
@@ -1130,10 +1116,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/watchers", options, session)
+        super().__init__("issue/{0}/watchers", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def delete(self, username):  # type: ignore[override]
         """Remove the specified user from the watchers list."""
@@ -1143,15 +1128,14 @@ def delete(self, username):  # type: ignore[override]
 class TimeTracking(Resource):
     def __init__(
         self,
-        options: dict[str, str],
+        options: dict[str, Any] | None,
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/worklog/{1}", options, session)
+        super().__init__("issue/{0}/worklog/{1}", options, session)
         self.remainingEstimate = None
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Worklog(Resource):
@@ -1163,10 +1147,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/worklog/{1}", options, session)
+        super().__init__("issue/{0}/worklog/{1}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def delete(  # type: ignore[override]
         self, adjustEstimate: str | None = None, newEstimate=None, increaseBy=None
@@ -1200,11 +1183,11 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issue/{0}/properties/{1}", options, session)
+        super().__init__("issue/{0}/properties/{1}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
+    @override
     def _find_by_url(
         self,
         url: str,
@@ -1224,10 +1207,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issueLink/{0}", options, session)
+        super().__init__("issueLink/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class IssueLinkType(Resource):
@@ -1239,10 +1221,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issueLinkType/{0}", options, session)
+        super().__init__("issueLinkType/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class IssueType(Resource):
@@ -1254,10 +1235,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "issuetype/{0}", options, session)
+        super().__init__("issuetype/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Priority(Resource):
@@ -1269,10 +1249,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "priority/{0}", options, session)
+        super().__init__("priority/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Project(Resource):
@@ -1284,10 +1263,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "project/{0}", options, session)
+        super().__init__("project/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Role(Resource):
@@ -1299,10 +1277,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "project/{0}/role/{1}", options, session)
+        super().__init__("project/{0}/role/{1}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def update(  # type: ignore[override]
         self,
@@ -1320,15 +1297,13 @@ def update(  # type: ignore[override]
         if groups is not None and isinstance(groups, str):
             groups = (groups,)
 
-        data = {
-            "id": self.id,
-            "categorisedActors": {
+        super().update(
+            ids=self.id,
+            categorisedActors={
                 "atlassian-user-role-actor": users,
                 "atlassian-group-role-actor": groups,
             },
-        }
-
-        super().update(**data)
+        )
 
     def add_user(
         self,
@@ -1359,10 +1334,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "resolution/{0}", options, session)
+        super().__init__("resolution/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class SecurityLevel(Resource):
@@ -1374,10 +1348,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "securitylevel/{0}", options, session)
+        super().__init__("securitylevel/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Status(Resource):
@@ -1389,10 +1362,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "status/{0}", options, session)
+        super().__init__("status/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class StatusCategory(Resource):
@@ -1404,10 +1376,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "statuscategory/{0}", options, session)
+        super().__init__("statuscategory/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class User(Resource):
@@ -1425,10 +1396,9 @@ def __init__(
         if raw and "accountId" in raw["self"]:
             _query_param = "accountId"
 
-        Resource.__init__(self, f"user?{_query_param}" + "={0}", options, session)
+        super().__init__(f"user?{_query_param}" + "={0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Group(Resource):
@@ -1440,10 +1410,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "group?groupname={0}", options, session)
+        super().__init__("group?groupname={0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Version(Resource):
@@ -1455,10 +1424,9 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(self, "version/{0}", options, session)
+        super().__init__("version/{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
     def delete(self, moveFixIssuesTo=None, moveAffectedIssuesTo=None):
         """Delete this project version from the server.
@@ -1478,7 +1446,7 @@ def delete(self, moveFixIssuesTo=None, moveAffectedIssuesTo=None):
         return super().delete(params)
 
     # TODO: https://github.com/pycontribs/jira/issues/1881
-    def update(self, **kwargs):  # type: ignore[override]
+    def update(self, **kwargs: Any) -> None:  # type: ignore[override]
         """Update this project version from the server. It is prior used to archive versions.
 
         Refer to Atlassian REST API `documentation`_.
@@ -1527,10 +1495,9 @@ def __init__(
     ):
         self.self = ""
 
-        Resource.__init__(self, path, options, session, self.AGILE_BASE_URL)
+        super().__init__(path, options, session, self.AGILE_BASE_URL)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class Sprint(AgileResource):
@@ -1542,7 +1509,7 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        AgileResource.__init__(self, "sprint/{0}", options, session, raw)
+        super().__init__("sprint/{0}", options, session, raw)
 
 
 class Board(AgileResource):
@@ -1554,7 +1521,7 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        AgileResource.__init__(self, "board/{id}", options, session, raw)
+        super().__init__("board/{id}", options, session, raw)
 
 
 # Service Desk
@@ -1569,12 +1536,11 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(
-            self, "customer", options, session, "{server}/rest/servicedeskapi/{path}"
+        super().__init__(
+            "customer", options, session, "{server}/rest/servicedeskapi/{path}"
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class ServiceDesk(Resource):
@@ -1586,8 +1552,7 @@ def __init__(
         session: ResilientSession,
         raw: dict[str, Any] | None = None,
     ):
-        Resource.__init__(
-            self,
+        super().__init__(
             "servicedesk/{0}",
             options,
             session,
@@ -1595,7 +1560,6 @@ def __init__(
         )
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 class RequestType(Resource):
@@ -1617,14 +1581,16 @@ def __init__(
 
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 # Utilities
 
 
 def dict2resource(
-    raw: dict[str, Any], top=None, options=None, session=None
+    raw: dict[str, Any],
+    top=None,
+    options: dict[str, Any] | None = None,
+    session: ResilientSession | None = None,
 ) -> PropertyHolder | type[Resource]:
     """Convert a dictionary into a Jira Resource object.
 
@@ -1634,12 +1600,13 @@ def dict2resource(
     if top is None:
         top = PropertyHolder()
 
-    seqs = tuple, list, set, frozenset
     for i, j in raw.items():
         if isinstance(j, dict):
             if "self" in j:
                 # to try and help mypy know that cls_for_resource can never be 'Resource'
                 resource_class = cast(type[Resource], cls_for_resource(j["self"]))
+                if session is None:
+                    raise JIRAError(f"Session is required for resource {j['self']}")
                 resource = cast(
                     type[Resource],
                     resource_class(  # type: ignore
@@ -1650,11 +1617,12 @@ def dict2resource(
                 )
                 setattr(top, i, resource)
             elif i == "timetracking":
+                if session is None:
+                    raise JIRAError("Session is required to parse timetracking")
                 setattr(top, "timetracking", TimeTracking(options, session, j))
             else:
                 setattr(top, i, dict2resource(j, options=options, session=session))
-        elif isinstance(j, seqs):
-            j = cast(list[dict[str, Any]], j)  # help mypy
+        elif isinstance(j, tuple | list | set | frozenset):
             seq_list: list[Any] = []
             for seq_elem in j:
                 if isinstance(seq_elem, dict):
@@ -1663,6 +1631,8 @@ def dict2resource(
                         resource_class = cast(
                             type[Resource], cls_for_resource(seq_elem["self"])
                         )
+                        if session is None:
+                            raise JIRAError(f"Session is required for resource {seq_elem['self']}")
                         resource = cast(
                             type[Resource],
                             resource_class(  # type: ignore
@@ -1738,7 +1708,6 @@ def __init__(
         Resource.__init__(self, "unknown{0}", options, session)
         if raw:
             self._parse_raw(raw)
-        self.raw: dict[str, Any] = cast(dict[str, Any], self.raw)
 
 
 def cls_for_resource(resource_literal: str) -> type[Resource]:
diff --git a/tests/tests.py b/tests/tests.py
index 4a4217d00..0cbae496d 100755
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -414,7 +414,7 @@ def test_fetch_pages(
         mock_session.request.return_value = responses
         mock_session.get.return_value = responses
         self.jira._session.close()
-        self.jira._session = mock_session
+        self.jira._session = mock_session  # type: ignore
         items = self.jira._fetch_pages(
             Issue, "issues", "search", start_at, max_results, params=params
         )