Shopify mobile-buy-sdk-android migration to 4.0.0 from 3.2.3

Question

Currently, I am using mobile buy SDK version 3.2.3 and my code is:

QueryGraphCall graphCall = graphClient.queryGraph(graphqlQuery.getAllOrders(size, cursor));
    graphCall.enqueue(new GraphCall.Callback<Storefront.QueryRoot>() {
        @Override
        public void onResponse(@NonNull GraphResponse<Storefront.QueryRoot> response) {
        // Success response
        }
        @Override
        public void onFailure(@NonNull GraphError error) {
        //Failure Response
        }
    });

Updated my shopify version to 4.0.0 and now it shows can not resolve symbol GraphCall.Callback I am new to shopify, Can anybody help me to this problem

• How can I get response from latest version of mobile buy SDK?
• Is there any problem with my SDK update ( just change implementation 'com.shopify.mobilebuysdk:buy3:3.2.3 >> 4.0.0 ) version 4X does not supports minSdkVersion 19 so also changed the same to 21.

Thanks in advance