/**
  * Checks if the given value is a valid email address.
  * If at least one error occurred, the result is FALSE.
  * The regexp is a modified version of the last one shown on
  * http://www.regular-expressions.info/email.html
  *
  * @param mixed $value The value that should be validated
  * @return boolean TRUE if the value is valid, FALSE if an error occured
  */
 public function isValid($value)
 {
     if (empty($value)) {
         return true;
     } else {
         return parent::isValid($value);
     }
 }
 /**
  * @param string $emailAddress
  * @return bool
  */
 protected function validEmail($emailAddress)
 {
     return parent::validEmail(trim($emailAddress));
 }