code: public static function phone($message = 'Must be a phone number')
      {
          // TODO: [PSI] create a predicate IsPhoneNumber in the psi library
          $check = function ($value) {
              return preg_match('/[\+0-9 ]{5,}/', $value);
          };
  
          return new ResultsIn\OutcomeRule($check, $message);
      }
docs: @param string $message
  
  @return OutcomeRule