def test_returnWithValue(self):
        """
        If the C{return} statement has a value it is propagated back to the
        L{Deferred} that the C{inlineCallbacks} function returned.
        """
        environ = {"inlineCallbacks": inlineCallbacks}
        exec("""
@inlineCallbacks
def f(d):
    yield d
    return 14
        """, environ)
        d1 = Deferred()
        d2 = environ["f"](d1)
        d1.callback(None)
        self.assertEqual(self.successResultOf(d2), 14)

        If the C{return} statement has a value it is propagated back to the
        L{Deferred} that the C{inlineCallbacks} function returned.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_inlinecb.py