def METHOD_NAME(monkeypatch):
    original_listdir = localedata.os.listdir
    listdir_calls = []
    def listdir_spy(*args):
        rv = original_listdir(*args)
        listdir_calls.append((args, rv))
        return rv
    monkeypatch.setattr(localedata.os, 'listdir', listdir_spy)
    localedata.locale_identifiers.cache_clear()
    assert not listdir_calls
    l = localedata.locale_identifiers()
    assert len(listdir_calls) == 1
    assert localedata.locale_identifiers() is l
    assert len(listdir_calls) == 1
    localedata.locale_identifiers.cache_clear()
    assert localedata.locale_identifiers()
    assert len(listdir_calls) == 2