mappings.put(new TypeVariableKey(typeVariable), to);
      }

      @Override
      void visitWildcardType(WildcardType fromWildcardType) {
        if (!(to instanceof WildcardType)) {
          return; // okay to say <?> is anything
        }
        WildcardType toWildcardType = (WildcardType) to;
        Type[] fromUpperBounds = fromWildcardType.getUpperBounds();
        Type[] toUpperBounds = toWildcardType.getUpperBounds();

        mappings.put(new TypeVariableKey(typeVariable), to);
      }

      @Override
      void visitWildcardType(WildcardType fromWildcardType) {
        if (!(to instanceof WildcardType)) {
          return; // okay to say <?> is anything
        }
        WildcardType toWildcardType = (WildcardType) to;
        Type[] fromUpperBounds = fromWildcardType.getUpperBounds();
        Type[] toUpperBounds = toWildcardType.getUpperBounds();

// due to a missing new pool. This function tries to handle this
// scenario, albeit rare it seems to have occurred in the wild.
//
// since we do not explicitly disallow it, but it is okay for them
// expand and then we continue to rebalance.
func (z *erasureServerPools) updateRebalanceStats(ctx context.Context) error {
	var ok bool
	for i := range z.serverPools {
		if z.findIndex(i) == -1 {