searchProductVariant 
searchProductVariant 

Undocumented search feature: https://ecommerce.shopify.com/c/shopify-apis-and-technology/t/api-product-variant-search-183152
kristofers91/PHP-Shopify-API-Wrapper,ShopifyExtras/PHP-Shopify-API-Wrapper,sebmaynard/PHP-Shopify-API-Wrapper