@Override
  public String toString() {
    final StringBuilder sb = new StringBuilder("DrainMessage{");
    sb.append(" UUID: ").append(uuid);
    sb.append(", runId: ").append(runId);
    sb.append(", drainMode: ");
    sb.append('}');
    return sb.toString();
  }
Creates a DrainNotification in {@link DrainMode#DEFAULT} mode.
samza-api/src/main/java/org/apache/samza/drain/DrainNotification.java