def METHOD_NAME(base_config):
    assert LocaleBorg().formatted_date("long", TESLA_BIRTHDAY_DT) == DT_EN_US
    assert LocaleBorg().formatted_date("long", TESLA_BIRTHDAY_DT, "en") == DT_EN_US
    assert LocaleBorg().formatted_date("long", TESLA_BIRTHDAY_DT, "pl") == DT_PL
    LocaleBorg().set_locale("pl")
    assert LocaleBorg().formatted_date("long", TESLA_BIRTHDAY_DT) == DT_PL
    assert LocaleBorg().formatted_date("long", TESLA_BIRTHDAY_DT, "en") == DT_EN_US