public final void compute() {
            final Function<? super K, ? extends U> transformer;
            final Consumer<? super U> action;
            if ((transformer = this.transformer) != null &&
                (action = this.action) != null) {
                for (int i = baseIndex, f, h; batch > 0 &&
                         (h = ((f = baseLimit) + i) >>> 1) > i;) {
                    addToPendingCount(1);
                    new ForEachTransformedKeyTask<K,V,U>
                        (this, batch >>>= 1, baseLimit = h, f, tab,
                         transformer, action).fork();
                }
                for (Node<K,V> p; (p = advance()) != null; ) {
                    U u;
                    if ((u = transformer.apply(p.key)) != null)
                        action.accept(u);
                }
                propagateCompletion();
            }
        }
public final void compute()