[JRuby 9.4.0.0]warning: parentheses after method name is interpreted as an argument list, not a decomposed argument

[8exBCYJi5ATL]

Describe the bug
The following warnings occur in JRuby 9.4.0.0.

warning: parentheses after method name is interpreted as an argument list, not a decomposed argument

To Reproduce
1.install JRuby 9.4.0.0.

2.install rethinkdb-ruby(rethinkdb-2.4.0.0)
gem install rethinkdb

3.require rethinkdb-ruby
require 'rethinkdb'

The problem
1.rethinkdb-2.4.0.0/lib/rethinkdb.rb

line: 21

    def unbound_if (x, name = nil)
    
   => def unbound_if(x, name = nil)

2.rethinkdb-2.4.0.0/lib/rpp.rb

line: 96

    def self.can_prefix (name, args)

    => def self.can_prefix(name, args)