Assert won’t work in Android because most of the time a person isn’t running in debug mode, but rather some optimized code. Thus, the proper solution is to manually throw an exception, with code like this:
if (obj==null) throw new AssertionError("Object cannot be null");
It should be noted that by design, Asserts are intended for debug code, and not for release time code. So this might not be the best use of throwing an Assert. But this is how you can do it still, so…