@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    DiagnosticsStreamMessage that = (DiagnosticsStreamMessage) o;
    return metricsHeader.getAsMap().equals(that.metricsHeader.getAsMap()) && metricsMessage.equals(that.metricsMessage);
  }
Check if the message has no contents.
@return True if the message is empty, false otherwise.
samza-core/src/main/scala/org/apache/samza/diagnostics/DiagnosticsStreamMessage.java