I've created a Custom App Bar (CAB) for my Flutter mobile app that should appear at the top of every page. Right now the the entire code is copy/pasted on every page. But is there a way to create the CAB component once and place it as a self-contained component on each page, so that if i want to make a change to the CAB, i wont have to perform the same edit over and over on every page the CAB appears? Just trying to tidy things up a bit. Thanks!