public function getActiveCount( $type = 'purchase' ) {

		if( !in_array( $type, [ 'primary', 'purchase', 'quantity', 'weight', 'volume' ] ) ) {

			return 0;
		}

		$cartItems	= $this->activeItems;
		$count		= 0;

		foreach ( $cartItems as $cartItem ) {

			if( $cartItem->keep ) {

				$count += $cartItem->$type;
			}
		}

		return $count;
	}