def ms_format(milliseconds: float) ->str:
    """Slightly smart formating of an elapsed time
    """
    assert milliseconds >= 0
    if milliseconds < 1:
        return f'{milliseconds:.3f}ms'
    if milliseconds < 1000:
        return f'{milliseconds:.2f}ms'
    return f'{milliseconds / 1000:.3f}sec'
