@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    FaultDomain that = (FaultDomain) o;
    return Objects.equal(type, that.type) && Objects.equal(id, that.id);
  }
Gets the id of the fault domain, for example: rack ID.
@return fault domain ID
samza-core/src/main/java/org/apache/samza/clustermanager/FaultDomain.java