function enumerable(rule, value, callback, source, options) {
  var errors = [];
  var validate = rule.required || !rule.required && source.hasOwnProperty(rule.field);
  if (validate) {
    if (__webpack_require__.i(__WEBPACK_IMPORTED_MODULE_1__util__["f" /* isEmptyValue */])(value) && !rule.required) {
      return callback();
    }
    __WEBPACK_IMPORTED_MODULE_0__rule___["a" /* default */].required(rule, value, source, errors, options);
    if (value) {
      __WEBPACK_IMPORTED_MODULE_0__rule___["a" /* default */][ENUM](rule, value, source, errors, options);
    }
  }
  callback(errors);
}
Validates an enumerable list.

 @param rule The validation rule.
 @param value The value of the field on the source object.
 @param callback The callback function.
 @param source The source object being validated.
 @param options The validation options.
 @param options.messages The validation messages.