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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(self, document_id, namespace, timestamp):
 """Removes the document from the doc dict. """

        try:
            entry = self.doc_dict[document_id]
            entry.doc = None
            entry.update(namespace, timestamp)
        except KeyError:
            raise OperationFailed("Document does not exist: %s" % document_id)