def METHOD_NAME(self):
    d = [["1", None], ["3", "4"]]
    assert safe_urlencode(d) == "1=&3=4"
    assert d == [["1", None], ["3", "4"]]
    d = [["1", "2"], ["3", "4"]]
    assert safe_urlencode(d) == "1=2&3=4"