if (lowerBounds.length == 0) { // ? extends something changes to capture-of
          return captureAsTypeVariable(wildcardType.getUpperBounds());
        } else {
          // TODO(benyu): handle ? super T somehow.
          return type;
        }
      }
      throw new AssertionError("must have been one of the known types");
    }

    TypeVariable<?> captureAsTypeVariable(Type[] upperBounds) {
      String name =

        if (lowerBounds.length == 0) { // ? extends something changes to capture-of
          return captureAsTypeVariable(wildcardType.getUpperBounds());
        } else {
          // TODO(benyu): handle ? super T somehow.
          return type;
        }
      }
      throw new AssertionError("must have been one of the known types");
    }

    TypeVariable<?> captureAsTypeVariable(Type[] upperBounds) {
      String name =