def METHOD_NAME(self):
    def producer(out):
        out.write('1\n')
        out.write('2\n')
        out.flush()
        out.write('3\n')
    iterable = IterIO(producer)
    self.assert_equal(next(iterable), '1\n2\n')
    self.assert_equal(next(iterable), '3\n')
    self.assert_raises(StopIteration, next, iterable)