def __init__(self, package, version):
        """Construct a new requirement.

        :param package: the package name.
        :param version: a semver compatible version specification.
        """
        self.package = package
        self.version = version
        if self.version and not re.match(r"[<=>~]", version[:2]):
            self.version = "=={}".format(self.version)
def test_reserve_unreserve_volume(self):
        """Test reserving and unreserving volume"""
        # Mark volume as reserved.
        self.volumes_client.reserve_volume(self.volume['id'])
        # To get the volume info
        body = self.volumes_client.show_volume(self.volume['id'])['volume']
        self.assertIn('attaching', body['status'])
        # Unmark volume as reserved.
        self.volumes_client.unreserve_volume(self.volume['id'])
        # To get the volume info
        body = self.volumes_client.show_volume(self.volume['id'])['volume']
        self.assertIn('available', body['status'])