fUndoChange= new DeleteFolderChange((IFolder) fPackageFragment.getUnderlyingResource());
fUndoChange= new DeleteSourceManipulationChange(fPackageFragment);
	public void perform(ChangeContext context, IProgressMonitor pm) throws JavaModelException, ChangeAbortException {		try {			pm.beginTask("Creating package...", 1);			if (!isActive() || fPackageFragment.exists()) {				fUndoChange= new NullChange();				} else {				IPackageFragmentRoot root= (IPackageFragmentRoot) fPackageFragment.getParent();				root.createPackageFragment(fPackageFragment.getElementName(), false, pm);								fUndoChange= new DeleteFolderChange((IFolder) fPackageFragment.getUnderlyingResource());			}				} catch (CoreException e) {			handleException(context, e);			fUndoChange= new NullChange();			setActive(false);		} finally {			pm.done();		}	}