public class AAA { private int x = 42; public int getX() { return x; } public void setX(int x) { this.x = x; } public void foo() { setX(getX() + 1); } public void bar(AAA other) { other.setX(other.getX() + 1); } } class B { void foo(AAA a) { a.setX(a.getX() + 1); } }