@org.apache.thrift.annotation.Nullable
    public static _Fields findByThriftId(int fieldId) {
      switch(fieldId) {
        case 1: // MESSAGE
          return MESSAGE;
        case 2: // CAN_RETRY
          return CAN_RETRY;
        default:
          return null;
      }
    }
Find the _Fields constant that matches fieldId, or null if its not found.
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TIOError.java