[Fact]
        public void DynamicInvocation()
        {
            var source =
@"class C
{
    static void F(object x, object y)
    {
    }
    static void G(object? x, dynamic y)
    {
        F(x, y);
        if (x != null) F(y, x);
    }
}";
            var comp = CreateCompilationWithMscorlib40AndSystemCore(new[] { source, NonNullTypesTrue, NonNullTypesAttributesDefinition });
            // PROTOTYPE(NullableReferenceTypes): We should be able to report warnings
            // when all applicable methods agree on the nullability of particular parameters.
            // (For instance, x in F(x, y) above.)
            comp.VerifyDiagnostics();
        }


        [Fact]
        public void DynamicObjectCreation_02()
        {
            var source =
@"class C
{
    C(object x, object y)
    {
    }
    static void G(object? x, dynamic y)
    {
        var o = new C(x, y);
        if (x != null) o = new C(y, x);
    }
}";
            var comp = CreateCompilationWithMscorlib40AndSystemCore(new[] { source, NonNullTypesTrue, NonNullTypesAttributesDefinition });
            // PROTOTYPE(NullableReferenceTypes): We should be able to report warnings
            // when all applicable methods agree on the nullability of particular parameters.
            // (For instance, x in F(x, y) above.)
            comp.VerifyDiagnostics();
        }