code: public IClientStream getStreamByChannelId(int channelId) {
          // channels 2 and 3 are "special" and don't have an IClientStream associated
          if (channelId < 4) {
              return null;
          }
          Number streamId = getStreamIdForChannelId(channelId);
          if (log.isTraceEnabled()) {
              log.trace("Stream requested for channel id: {} stream id: {} streams: {}", channelId, streamId, streams);
          }
          return getStreamById(streamId);
      }
docs: Return stream by given channel id.
  
  @param channelId
  Channel id
  @return Stream that channel belongs to