//this is actual cart_array//
{product_id: '1', product_type: 'normal_product', product_variant_id: '', quantity: 2}
{product_id: '42', product_type: 'variant_product', product_variant_id: '3', quantity: 2}
{product_id: '42', product_type: 'variant_product', product_variant_id: '2', quantity: 3}