public static Type getExactFieldType(Field f, Type type) {
    return GenericTypeReflector.getExactFieldType(f, type);
  }
Returns the exact type of the given field in the given type.
This may be different from <tt>f.getGenericType()</tt> when the field was declared in a superclass,
of <tt>type</tt> is a raw type.

@param f    the field to resolve
@param type the type to resolve the field with
@return the resolved type
spock-core/src/main/java/org/spockframework/util/GenericTypeReflectorUtil.java