In a continuous integration, agile environment, if I make a change in class A (e.g. change attribute names) which I have created and have been working on, that affects class B, which "belongs" to someone else, who modifies class B whenever I want to check in my change? Me or the class' B owner?
I suppose is more agile if I modify it, so that I don't have to notify other people, but at the same time, people working on it are more aware of the impact of modifying it...
In an agile environment, class B (like all classes) belongs to the team. We call this Shared Code Ownership. You should check in working code; if that means you need to adjust class B to conform to the changes you make to class A - adjust! Better yet, pair.