def METHOD_NAME(self):
    may_access = self.__access_check__()
    if not may_access:
        raise ProgrammingError(
            "Access not possible in this context. Look "
            "up the docs in linotp.lib.context for the "
            "right context manager"
        )
    thread_identity = self.__ident_func__()
    return self.__storage__.setdefault(thread_identity, self._source)