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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 _update_metadata(self, archive_name, archive_metadata):
 """ Appends the updated_metada dict to the Metadata Attribute list Parameters archive_name: str ID of archive to update updated_metadata: dict dictionary of metadata keys and values to update. If the value for a particular key is `None`, the key is removed. """


        archive_metadata_current = self._get_archive_metadata(archive_name)
        archive_metadata_current.update(archive_metadata)
        for k, v in archive_metadata_current.items():
            if v is None:
                del archive_metadata_current[k]

        # add the updated archive_metadata object to Dynamo
        self._table.update_item(
            Key={'_id': archive_name},
            UpdateExpression="SET archive_metadata = :v",
            ExpressionAttributeValues={':v': archive_metadata_current},
            ReturnValues='ALL_NEW')