protected static function boot_if_not_booted() {

		if ( isset( static::$_booted[ get_called_class() ] ) ) {
			return;
		}

		static::$_booted[ get_called_class() ] = true;

		$instance = new static();

		$instance->fire_model_event( 'booting' );
		static::boot();
		$instance->fire_model_event( 'booted' );
	}