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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 delete(self, database, key, callback=None):
 """ Delete an item from the given database. :param database: The database from which to delete the value. :type database: .BlobDatabaseID :param key: The key to delete. :type key: uuid.UUID :param callback: A callback to be called on success or failure. """

        token = self._get_token()
        self._enqueue(self._PendingItem(token, BlobCommand(token=token, database=database,
                                                           content=DeleteCommand(key=key.bytes)),
                                        callback))