private final boolean target;

    Bounds(Type[] bounds, boolean target) {
      this.bounds = bounds;
      this.target = target;
    }

    boolean isSubtypeOf(Type supertype) {
      for (Type bound : bounds) {
        if (of(bound).isSubtypeOf(supertype) == target) {
          return target;
        }
      }
      return !target;
    }