code: def indentation_pre_event_input_accelerators(editor, event):
      
  
      process_event = True
      if not hasattr(editor, "indent"):
          return process_event
  
      if event.key() == Qt.Key_Tab:
          process_event = editor.indent() and False
      elif event.key() == Qt.Key_Backtab:
          process_event = editor.unindent() and False
      return process_event
docs: Implements indentation pre event input accelerators.
  
      :param editor: Document editor.
      :type editor: QWidget
      :param event: Event being handled.
      :type event: QEvent
      :return: Process event.
      :rtype: bool