<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_streamer(self, streamer):
 """Add a streamer to this sensor graph. Args: streamer (DataStreamer):
 The streamer we want to add """


        if self._max_streamers is not None and len(self.streamers) >= self._max_streamers:
            raise ResourceUsageError("Maximum number of streamers exceeded", max_streamers=self._max_streamers)

        streamer.link_to_storage(self.sensor_log)
        streamer.index = len(self.streamers)

        self.streamers.append(streamer)