Get room id from its alias.

        Args:
            room_alias (str): The room alias name.

        Returns:
            Wanted room's id.

def get_room_id(self, room_alias):
        """Get room id from its alias.

        Args:
            room_alias (str): The room alias name.

        Returns:
            Wanted room's id.
        """
        content = self._send("GET", "/directory/room/{}".format(quote(room_alias)))
        return content.get("room_id", None)