}
        for (int i = 0; i < fromLowerBounds.length; i++) {
          populateTypeMappings(mappings, fromLowerBounds[i], toLowerBounds[i]);
        }
      }

      @Override
      void visitParameterizedType(ParameterizedType fromParameterizedType) {
        if (to instanceof WildcardType) {
          return; // Okay to say Foo<A> is <?>
        }

        }
        for (int i = 0; i < fromLowerBounds.length; i++) {
          populateTypeMappings(mappings, fromLowerBounds[i], toLowerBounds[i]);
        }
      }

      @Override
      void visitParameterizedType(ParameterizedType fromParameterizedType) {
        if (to instanceof WildcardType) {
          return; // Okay to say Foo<A> is <?>
        }