code: function NotNullError(message, innerMessage, model,field) {
      NotNullError.super_.bind(this)('ENULL', message || 'A value is required.', innerMessage, model,field);
      this.statusCode = 409;
  }
docs: Thrown when an application attempts to access a data object that cannot be found.
  @param {string=} message - The error message
  @param {string=} innerMessage - The error inner message
  @param {string=} model - The target model
  @param {string=} field - The target field
  @constructor
  @extends DataError