Perform GET /rooms/{roomId}/messages.

        Args:
            room_id (str): The room's id.
            token (str): The token to start returning events from.
            direction (str):  The direction to return events from. One of: ["b", "f"].
            limit (int): The maximum number of events to return.
            to (str): The token to stop returning events at.

def get_room_messages(self, room_id, token, direction, limit=10, to=None):
        """Perform GET /rooms/{roomId}/messages.

        Args:
            room_id (str): The room's id.
            token (str): The token to start returning events from.
            direction (str):  The direction to return events from. One of: ["b", "f"].
            limit (int): The maximum number of events to return.
            to (str): The token to stop returning events at.
        """
        query = {
            "roomId": room_id,
            "from": token,
            "dir": direction,
            "limit": limit,
        }

        if to:
            query["to"] = to

        return self._send("GET", "/rooms/{}/messages".format(quote(room_id)),
                          query_params=query, api_path="/_matrix/client/r0")