public void OutAndRefMethodUsage() { var stub = new StubExample(); IExample example = stub; // IExample has an out method named "OutMethod(int, out int)" // in the stub, methods with out or ref parameters are exposed using the method name suffixed with the parameter types. // also, lambas using out/ref parameters require full types specificied for the parameters. stub.OutMethod_int_int = (int input, out int output) => { output = input + 2; }; int number; example.OutMethod(5, out number); Assert.Equal(7, number); // ref params work the same way. stub.RefMethod_int_string = (int input, ref string reference) => true; }