def test_unix_time_to_utc():
    """
    Tests that the unix_time function returns the correct value and fails gracefully for strange inputs
    """
    assert unix_time_to_utc(0) == DateTime(1970, 1, 1)
    assert unix_time_to_utc(1483228800) == DateTime(2017, 1, 1)
    assert type(unix_time_to_utc(1483228800)) == DateTime
    assert unix_time_to_utc(None) is None
    with pytest.raises(TypeError):
        unix_time_to_utc("test")
    with pytest.raises(TypeError):
        unix_time_to_utc(DateTime(2017, 1, 1))

    Tests that the unix_time function returns the correct value and fails gracefully for strange inputs
    
tests/utils/test_ctftime.py