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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 remove_data_item(self, data_item: DataItem.DataItem, *, safe: bool=False) -> typing.Optional[typing.Sequence]: """Remove data item from document model. This method is NOT threadsafe. """

        # remove data item from any computations
        return self.__cascade_delete(data_item, safe=safe)