code: function mock (_, mockArgs, fieldArgs, currentValue) {
    if (currentValue !== undefined) {
      return currentValue;
    }
    if (mockArgs && mockArgs.with) {
      if (fieldArgs) {
        try {
          return Mustache.render(mockArgs.with, fieldArgs);
        } catch (e) {
          logger.error(new AntError(
            'Coould not renderize field template',
            e
          ));
        }
      } else {
        return mockArgs.with;
      }
    }
    return null;
  }
docs: This function mocks a GraphQL field value.