docs: def get_relationship_lookup_session_for_family(self, family_id, proxy):
          """Gets the ``OsidSession`` associated with the relationship lookup service for the given family.
  
          arg:    family_id (osid.id.Id): the ``Id`` of the family
          arg:    proxy (osid.proxy.Proxy): a proxy
          return: (osid.relationship.RelationshipLookupSession) - a
                  ``RelationshipLookupSession``
          raise:  NotFound - no ``Family`` found by the given ``Id``
          raise:  NullArgument - ``family_id`` or ``proxy`` is ``null``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - ``supports_relationship_lookup()`` or
                  ``supports_visible_federation()`` is ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_relationship_lookup()`` and
          ``supports_visible_federation()`` are ``true``*
  
          """
          if not self.supports_relationship_lookup():
              raise errors.Unimplemented()
          ##
          # Also include check to see if the catalog Id is found otherwise raise errors.NotFound
          ##
          # pylint: disable=no-member
          return sessions.RelationshipLookupSession(family_id, proxy, self._runtime)