@Override
  public int hashCode() {
    int hashCode = 1;

    hashCode = hashCode * 8191 + ((isSetHostName()) ? 131071 : 524287);
    if (isSetHostName())
      hashCode = hashCode * 8191 + hostName.hashCode();

    hashCode = hashCode * 8191 + ((isSetPort()) ? 131071 : 524287);
    if (isSetPort())
      hashCode = hashCode * 8191 + port;

    hashCode = hashCode * 8191 + ((isSetStartCode()) ? 131071 : 524287);
    if (isSetStartCode())
      hashCode = hashCode * 8191 + org.apache.thrift.TBaseHelper.hashCode(startCode);

    return hashCode;
  }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TServerName.java