docs: public Deferred<Object> addHistogramPoint(final String metric,
                                              final long timestamp,
                                              final byte[] raw_data,
                                              final Map<String, String> tags) {
      if (raw_data == null || raw_data.length < MIN_HISTOGRAM_BYTES) {
        return Deferred.fromError(new IllegalArgumentException(
            "The histogram raw data is invalid: " + Bytes.pretty(raw_data)));
      }
      
      checkTimestampAndTags(metric, timestamp, raw_data, tags, (short) 0);
      final byte[] row = IncomingDataPoints.rowKeyTemplate(this, metric, tags);
  
      final byte[] qualifier = Internal.getQualifier(timestamp, 
          HistogramDataPoint.PREFIX);
      
      return storeIntoDB(metric, timestamp, raw_data, tags, (short) 0, row, qualifier);
    }