def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def delete_snapshot_metadata_item(self, snapshot_id, id):
        """Delete metadata item for the snapshot."""
        url = "snapshots/%s/metadata/%s" % (str(snapshot_id), str(id))
        resp, body = self.delete(url)
        return resp, body