def gen():
    when = (yield)
    self.assertAlmostEqual(0.1, when)
    when = (yield 0.1)
    self.assertAlmostEqual(0.2, when)
    (yield 0.1)
def gen():
    when = (yield)
    self.assertAlmostEqual(0.1, when)
    when = (yield 0.1)
    self.assertAlmostEqual(0.2, when)
    (yield 0.1)