def restore_profiler():
    """If a typechecking profiler is active, e.g. created by
    pytypes.set_global_typechecked_profiler(), such a profiler
    must be restored whenever a TypeCheckError is caught.
    The call must stem from the thread that raised the error.
    Otherwise the typechecking profiler is implicitly disabled.
    Alternatively one can turn pytypes into warning mode. In that
    mode no calls to this function are required (unless one uses
    filterwarnings("error") or likewise).
    """
    idn = threading.current_thread().ident
    if not sys.getprofile() is None:
        warn("restore_profiler: Current profile is not None!")
    if not idn in _saved_profilers:
        warn("restore_profiler: No saved profiler for calling thread!")
    else:
        sys.setprofile(_saved_profilers[idn])
        del _saved_profilers[idn]