Add has_variants validator for ProductClass
Add has_variants validator for ProductClass

KenMutemi/saleor,tfroehlich82/saleor,car3oon/saleor,HyperManTT/ECommerceSaleor,UITools/saleor,HyperManTT/ECommerceSaleor,maferelo/saleor,mociepka/saleor,tfroehlich82/saleor,car3oon/saleor,KenMutemi/saleor,jreigel/saleor,HyperManTT/ECommerceSaleor,itbabu/saleor,jreigel/saleor,itbabu/saleor,KenMutemi/saleor,mociepka/saleor,maferelo/saleor,jreigel/saleor,UITools/saleor,UITools/saleor,UITools/saleor,car3oon/saleor,maferelo/saleor,itbabu/saleor,UITools/saleor,tfroehlich82/saleor,mociepka/saleor