def test_indexOf_5():
    assert indexOf(1, "1") == None
def test_indexOf_4():
    assert indexOf(1, [3, 1, 1, 2]) == 1
def test_indexOf_2():
    assert indexOf(3, ["1", "2", "3"]) == None
def test_indexOf_3():
    assert indexOf(3, []) == None
def test_indexOf_1():
    assert indexOf("tree", [4, "x", "tree", -1.2]) == 2