docs: def rename_document(self, old_path, new_path):
          """
          Renames an already opened document (this will not rename the file,
          just update the file path and tab title).
  
          Use that function to update a file that has been renamed externally.
  
          :param old_path: old path (path of the widget to rename with
              ``new_path``
          :param new_path: new path that will be used to rename the tab.
          """
          to_rename = []
          title = os.path.split(new_path)[1]
          for widget in self.widgets(include_clones=True):
              p = os.path.normpath(os.path.normcase(widget.file.path))
              old_path = os.path.normpath(os.path.normcase(old_path))
              if p == old_path:
                  to_rename.append(widget)
          for widget in to_rename:
              tw = widget.parent_tab_widget
              widget.file._path = new_path
              tw.setTabText(tw.indexOf(widget), title)