code: public void doSaveAs() {
  		IEditorPart editor = getEditor(0);
  		editor.doSaveAs();
  		setPageText(0, editor.getTitle());
  		setInput(editor.getEditorInput());
  	}
docs: Saves the multi-page editor's document as another file. Also updates the
  text for page 0's tab, and updates this multi-page editor's input to
  correspond to the nested editor's.