Extracts the response message known a request and Update result.
        The request may also be the ID of the message to match.

        If ``request is None`` this method returns ``{id: message}``.

        If ``request.random_id`` is a list, this method returns a list too.

def _get_response_message(self, request, result, input_chat):
        """
        Extracts the response message known a request and Update result.
        The request may also be the ID of the message to match.

        If ``request is None`` this method returns ``{id: message}``.

        If ``request.random_id`` is a list, this method returns a list too.
        """
        if isinstance(result, types.UpdateShort):
            updates = [result.update]
            entities = {}
        elif isinstance(result, (types.Updates, types.UpdatesCombined)):
            updates = result.updates
            entities = {utils.get_peer_id(x): x
                        for x in
                        itertools.chain(result.users, result.chats)}
        else:
            return None

        random_to_id = {}
        id_to_message = {}
        for update in updates:
            if isinstance(update, types.UpdateMessageID):
                random_to_id[update.random_id] = update.id

            elif isinstance(update, (
                    types.UpdateNewChannelMessage, types.UpdateNewMessage)):
                update.message._finish_init(self, entities, input_chat)
                id_to_message[update.message.id] = update.message

            elif (isinstance(update, types.UpdateEditMessage)
                  and not isinstance(request.peer, types.InputPeerChannel)):
                if request.id == update.message.id:
                    update.message._finish_init(self, entities, input_chat)
                    return update.message

            elif (isinstance(update, types.UpdateEditChannelMessage)
                  and utils.get_peer_id(request.peer) ==
                  utils.get_peer_id(update.message.to_id)):
                if request.id == update.message.id:
                    update.message._finish_init(self, entities, input_chat)
                    return update.message

        if request is None:
            return id_to_message

        random_id = request if isinstance(request, int) else request.random_id
        if not utils.is_list_like(random_id):
            if random_id in random_to_id:
                return id_to_message[random_to_id[random_id]]
            else:
                return None
        else:
            # ``rnd in random_to_id`` is needed because trying to forward only
            # deleted messages causes `MESSAGE_ID_INVALID`, but forwarding
            # valid and invalid messages in the same call makes the call
            # succeed, although the API won't return those messages thus
            # `random_to_id[rnd]` would `KeyError`.
            return [id_to_message[random_to_id[rnd]]
                    if rnd in random_to_id else None
                    for rnd in random_id]