Bug 337231 [Compatibility] Parts need local IPartService implementations
We should use a slave IPartService implementation for parts.
tests/org.eclipse.e4.ui.compat.tests.tweaklet/src/org/eclipse/e4/ui/compat/tests/tweaklet/TestFacadeE4Impl.java
public Save promptToSave(MPart dirtyPart) {
			switch (response) {
			case 0: return Save.YES;
			case 1: return Save.NO;
			case 2: return Save.CANCEL;
			case ISaveablePart2.DEFAULT:
				return Save.YES;
			}
			throw new RuntimeException();
		}
		public Save[] promptToSave(Collection<MPart> dirtyParts) {
			Save save = promptToSave((MPart) null);
			Save[] prompt = new Save[dirtyParts.size()];
			Arrays.fill(prompt, save);
			return prompt;
		}
		
	}
	@Override
	public boolean isClosableInPerspective(IViewReference ref) {
		E4Util.unsupported("isClosableInPerspective");
		return false;
	}
	@Override
	public boolean isMoveableInPerspective(IViewReference ref) {
		E4Util.unsupported("isMoveableInPerspective");
		return false;
	}
}