This detect usages of the form:

            >>> from gevent import joinall
            >>> joinall(...)

        or:

            >>> import gevent
            >>> gevent.joinall(...)

def _force_joinall_to_use_set(self, node):
        """This detect usages of the form:

            >>> from gevent import joinall
            >>> joinall(...)

        or:

            >>> import gevent
            >>> gevent.joinall(...)
        """
        for inferred_func in node.func.infer():
            if is_joinall(inferred_func):

                is_every_value_a_set = all(
                    inferred_first_arg.pytype() == 'builtins.set'
                    for inferred_first_arg in node.args[0].infer()
                )
                if not is_every_value_a_set:
                    self.add_message(JOINALL_ID, node=node)