I have a product page in a flutter. on the product page I show some similar products. when the user navigates through similar products, I push the new page into the stack. when the user hits the back button and I pop the page, I expect it to go to the previous product but it seems like all the product pages are alike in the stack and after a pop, it goes back to the main page. How can I how to push and pop in a single page multiple times in flutter?