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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _on_change(self, obj, old, value, **kwargs):
 """Called internally to emit changes from the instance object The keyword arguments here will be passed to callbacks through the instance object's :meth:`~pydispatch.dispatch.Dispatcher.emit` method. Keyword Args: property: The :class:`Property` instance. This is useful if multiple properties are bound to the same callback. The attribute name keys (optional):
 If the :class:`Property` is a container type (:class:`ListProperty` or :class:`DictProperty`), the changes may be found here. This is not implemented for nested containers and will only be available for operations that do not alter the size of the container. """

        kwargs['property'] = self
        obj.emit(self.name, obj, value, old=old, **kwargs)