class_docstr: Indicates that a setting is about to change, allows a listener to cancel the change
  
      
code: def __init__(self, old_value, new_value):
      ChangeSettingEvent.__init__(self, old_value, new_value)
      self.__allow_change = True
      self.__cancel_reason = None
  
imports: from ._change_setting_event import ChangeSettingEvent
label_desc: Use image node_id 1 to create a new BeforeChangeSettingEvent object from inherited base classes: ChangeSettingEvent with example: obj = BeforeChangeSettingEvent(old_value, new_value)