How to change the code of a module (library) in Android?

Question

Android

There is a project A that uses project B as a library (inherited from one class and implements one interface). I added project B as a module of project A.
I'm trying to make changes in project B - I add variables and methods, but class A does not want to see it. Such a word that project B simply compiled at the beginning and retains its original form.
Question: How can I change the module (project B)?

Answer 1

You'd better say what you build with. That's the point
- There are build managers that compile modules when they change (gradle, sbt)
- And there are those that do not (maven) and they need to do some actions after changes (mvn install)
I mean, not knowing how you do it the build is very difficult to understand what your problem might be

Answer 2

Try turning it off and then on