FragmentGenerator on interfaces ignored

[FlorianDecker]

The following sample raises a warning in method "CustomTypeGenerator". This is a bug since the interface declares the method as FragmentGenerator.

class AnnotatingInterfaces
{
    interface AnnotatedInterface
    {
      [FragmentGenerator]
      [return: CustomType]
      object CustomTypeGenerator();
    }

    class Implementation : AnnotatedInterface
    {
      public object CustomTypeGenerator()
      {
        return new object();
      }
    }
}