Fuel\Validation\Result::getError PHP Method

    public function getError($field)
    {
        if (!isset($this->errors[$field])) {
            throw new InvalidFieldException($field);
        }
        return $this->errors[$field];
    }

 /**
  * @expectedException \Fuel\Validation\InvalidFieldException
  */
 public function testGetInvalidError()
 {
     $this->object->getError('test');
 }