void () { doTest("None", """ def a(): yield 1 return 'a' y = [1, 2, 3] def b(): expr = yield from y return expr """); doTest("str", """ def a(): yield 1 return 'a' def b(): expr = yield from a() return expr """); doTest("int", """ def g(): yield 1 return 'abc' def f() x = yield from g() for expr in f(): pass"""); }