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 get_snapshot_metadata(self, snapshot_id):
        """Get metadata of the snapshot."""
        url = "snapshots/%s/metadata" % str(snapshot_id)
        resp, body = self.get(url)
        body = json.loads(body)
        return resp, body['metadata']