public void MethodNullReturnAnnotator_DoesNotAnnotateNonNullReturningMethod(string methodSource)
        {
            var source = string.Format(c_classTemplate, methodSource);

            var(model, syntax) = CompiledSourceFileProvider.CompileMethodInClass(source, "t");
            var rewriter = new MethodReturnNullAnnotator(model);

            var rewritten = (MethodDeclarationSyntax)rewriter.Visit(syntax);

            Assert.That(rewritten.ReturnType, Is.Not.InstanceOf <NullableTypeSyntax>());
        }