def METHOD_NAME(U):
    """
    Test the wave period
    """
    print("testing for U:", U)
    water = copy(default_water)
    water.fetch = 1e4  # 10km
    w = Waves(test_wind_5, water)  # 10km fetch
    T = w.mean_wave_period(U)
    print(T)
    # assert False # what else to check for???