code: public SettingFields[] fields() {
          return fields == null
              ? new SettingFields[0]
              : Arrays.copyOf(fields, fields.length);
      }
docs: Gets the fields on {@link ConfigurationSetting} to return from the GET request. If none are set, the service
  returns the ConfigurationSettings with all of their fields populated.
  
  @return The set of {@link ConfigurationSetting} fields to return for a GET request.