@org.apache.thrift.annotation.Nullable
      public static _Fields findByThriftId(int fieldId) {
        switch(fieldId) {
          case 0: // SUCCESS
            return SUCCESS;
          default:
            return null;
        }
      }
Find the _Fields constant that matches fieldId, or null if its not found.
zipkin-collector/scribe/src/main/java/zipkin2/collector/scribe/generated/Scribe.java