@org.apache.thrift.annotation.Nullable
    public static _Fields findByThriftId(int fieldId) {
      switch(fieldId) {
        case 1: // REQUEST_TYPE
          return REQUEST_TYPE;
        case 2: // ROLE_NAME
          return ROLE_NAME;
        case 3: // PRINCIPAL_NAME
          return PRINCIPAL_NAME;
        case 4: // PRINCIPAL_TYPE
          return PRINCIPAL_TYPE;
        case 5: // GRANTOR
          return GRANTOR;
        case 6: // GRANTOR_TYPE
          return GRANTOR_TYPE;
        case 7: // GRANT_OPTION
          return GRANT_OPTION;
        default:
          return null;
      }
    }
Find the _Fields constant that matches fieldId, or null if its not found.
standalone-metastore/metastore-common/src/gen/thrift/gen-javabean/org/apache/hadoop/hive/metastore/api/GrantRevokeRoleRequest.java