'Get a migration of a specified server
:param server: The :class:`Server` (or its ID)
:param migration: Migration id that will be gotten.
:returns: An instance of
novaclient.v2.server_migrations.ServerMigration'

@api_versions.wraps('2.23')
def get(self, server, migration):

    return self._get(('/servers/%s/migrations/%s' % (base.getid(server), base.getid(migration))), 'migration')
