/**
* Checks if the field value is boolean.
*
* @param Field $field The form field
* @param string message The error message
*
* @return Field
*/
public function boolean(Field $field, $message = 'formz.error.boolean')
{
$field->addConstraint(new \Formz\Constraint\Boolean($message));
$field->transform(new \Formz\Transformer\Boolean());
return $field;
}
