public function validatesPresenceOf($attrs)
	{
		$configuration = array_merge(self::$DEFAULT_VALIDATION_OPTIONS, array('message' => Errors::$DEFAULT_ERROR_MESSAGES['blank'], 'on' => 'save'));

		foreach ($attrs as $attr)
		{
			$options = array_merge($configuration, $attr);
			$this->record->addOnBlank($options[0], $options['message']);
		}
	}