code: public void removePostSelectionChangedListener(
  			ISelectionChangedListener listener)
  	{
  		if (fOutlineViewer != null)
  		{
  			fOutlineViewer.removePostSelectionChangedListener(listener);
  		} else
  		{
  			fPostSelectionChangedListeners.remove(listener);
  		}
  	}
docs: /*
  @see org.eclipse.jface.text.IPostSelectionProvider# removePostSelectionChangedListener
  (org.eclipse.jface.viewers.ISelectionChangedListener)