@Override
  public int hashCode() {
    int result = system.hashCode();
    result = 31 * result + stream.hashCode();
    result = 31 * result + partitionId;
    return result;
  }
Provides a client view of the samza system stream partition.
Includes the system name, stream name and partition id
samza-rest/src/main/java/org/apache/samza/rest/model/Partition.java