How to get return type from any Method with Guava?

What I understand from the official Guava's TypeToken wiki is we can get the return type of a method even if it is defined by a type argument. But I cannot manage to retrieve the returned type of a Method .

If I have an instanced List<String>, how can I do to get String.class from the get() method instead of E?

I know Java does type erasure during compile-time (i.e. the type argument is not available during runtime). Maybe I'm wrong, and Guava cannot retrieve the expected type of a method from a instanced class...