How to use the jsonpatch.AddOperation.apply function in jsonpatch

raise JsonPatchConflict(str(ex))

        # If source and target are equal, this is a no-op
        if self.pointer == from_ptr:
            return obj

        if isinstance(subobj, MutableMapping) and \
                self.pointer.contains(from_ptr):
            raise JsonPatchConflict('Cannot move values into its own children')

        obj = RemoveOperation({
            'op': 'remove',
            'path': self.operation['from']
        }).apply(obj)

        obj = AddOperation({
            'op': 'add',
            'path': self.location,
            'value': value
        }).apply(obj)

        return obj

def apply(self, obj):
        try:
            from_ptr = JsonPointer(self.operation['from'])
        except KeyError as ex:
            raise InvalidJsonPatch(
                "The operation does not contain a 'from' member")

        subobj, part = from_ptr.to_last(obj)
        try:
            value = copy.deepcopy(subobj[part])
        except (KeyError, IndexError) as ex:
            raise JsonPatchConflict(str(ex))

        obj = AddOperation({
            'op': 'add',
            'path': self.location,
            'value': value
        }).apply(obj)

        return obj