def test_get_time_value():
'make sure get_time_value goes to correct C++ derived class function'
shio = CyShioTime(shio_file)
t = time_utils.date_to_sec(datetime(2012, 8, 20, 13))
time = [t + 3600.*dt for dt in range(10)]
vel_rec = shio.get_time_value(time)
assert all(vel_rec['u'] != 0)
assert all(vel_rec['v'] == 0)
