code: @Override
      public Object getMember(String name) {
          switch (name) {
              case "format":
                  return F_format;
              case "schema":
                  return F_schema;
              case "option":
                  return F_option;
              case "load":
                  return F_load;
              case "json":
                  return F_json;
              case "csv":
                  return F_csv;
              case "parquet":
                  return F_parquet;
              case "text":
                  return F_text;
          }
          return super.getMember(name);
      }
docs: get the value of that named property