code: def dispatch(self, receiver):
          ''' Dispatch handling of this event to a receiver.
  
          This method will invoke ``receiver._document_model_dhanged`` if it
          exists.
  
          '''
          super(ModelChangedEvent, self).dispatch(receiver)
          if hasattr(receiver, '_document_model_changed'):
              receiver._document_model_changed(selff dispatch(self, receiver):
          ''' Dispatch handling of this event to a receiver.
  
          This method will invoke ``receiver._document_model_dhanged`` if it
          exists.
  
          '''
          super(ModelChangedEvent, self).dispatch(receiver)
          if hasattr(receiver, '_document_model_changed'):
              receiver._document_model_changed(self)
docs: Dispatch handling of this event to a receiver.
  
          This method will invoke ``receiver._document_model_dhanged`` if it
          exists.