@abstractmethod<EOL><INDENT>def is_permitted(self, permissions):<DEDENT>
pass<EOL>
Determines whether any Permission(s) associated with the subject
implies the requested Permission(s) provided.

:param permission_s: a collection of 1..N permissions, all of the same type
:type permission_s: List of authz_abcs.Permission object(s) or String(s)

:returns: a set of tuple(s), each containing the Permission
          requested and a Boolean indicating whether permission is
          granted
          - the tuple format is: (Permission, Boolean)