Resolve a TypeVariable

Say I have these classes:

class Container<T> {
  private List<T> list;
}

And I have an instance of Container, say

Container<?> instance = new Container<String>();

Is there a way to find out list's actual type parameter at run-time? I.e., that it's a List of String, rather than a List of java.lang.reflect.TypeVariable.

I've been looking at Java's reflection (field.getGenericType()), various libraries (Guava Reflect, Typetools, ClassMate, even ASM, etc.) but I can't figure it out.

I have no control over the Container type, so I can't add any fields to it.

I realize it may not be possible at all due to erasure, although I don't mind messing with bytecode if that makes it possible.