Breakpoints

An application will only stop at a breakpoint if the actual execution of the program reaches that breakpoint.

If you want to test a method which isn't yet 'wired in' to the rest of the application or will only be called rarely, then I'd simply insert a temporary call to that method at an appropriate place in your code. You can remove the temporary call when you're confident the method is working correctly.

If the method relies on some external context (i.e. variables outside the method itself) then you will of course need to ensure that you call the method at some point where this context has already been initialized.