public function validateModelObject(ModelObject $model)
    {
        $fields = $model->getPersistentFields();

        foreach ( $fields as $fieldName ) {

            $value         = $model->$fieldName;
            $fieldResolved = get_class($model).'.'.$fieldName;

            $this->rejectIfInvalid($fieldResolved,
                                   'field',
                                   $model->getFieldTitle($fieldName),
                                   $value,
                                   new ValidationExpression($model->getValidation($fieldName)));
        }
    }