Getting members of list by vars

[jizak]

Hi, Is it possible to get members of list by vars?
What I have is:

@mailgun.list_members('MY_LIST').list()
=> [{"address"=>"some@email.com", "name"=>"", "subscribed"=>true, "vars"=>{}},
 ]

I'm trying to do something like this:

@mailgun.list_members('MY_LIST').list({ vars: { type: 'daily'}})
=> [,
 ]

and getting the same array.

But when I try to do like this:

@mailgun.list_members(MY_LIST).list({ address: 'pavlo.shabat@gmail.com'})
=> []

It gives correct response.
How can I use vars correctly?