/*
     * Futures should be collected even if combiner never runs. This is kind of a silly test, since
     * the combiner is almost certain to hold its own reference to the futures, and a real app would
     * hold a reference to the executor and thus to the combiner. What we really care about is that
     * the futures are released once the combiner is done running. But we happen to provide this

    /*
     * Futures should be collected even if combiner never runs. This is kind of a silly test, since
     * the combiner is almost certain to hold its own reference to the futures, and a real app would
     * hold a reference to the executor and thus to the combiner. What we really care about is that
     * the futures are released once the combiner is done running. But we happen to provide this

      TreeMap<K, V> newTreeMap(@CheckForNull Comparator<C> comparator) {
    // Ideally, the extra type parameter "C" shouldn't be necessary. It is a
    // work-around of a compiler type inference quirk that prevents the
    // following code from being compiled:
    // Comparator<Class<?>> comparator = null;
    // Map<Class<? extends Throwable>, String> map = newTreeMap(comparator);
    return new TreeMap<>(comparator);
  }

import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ClosingFuture.Combiner.AsyncCombiningCallable;
import com.google.common.util.concurrent.ClosingFuture.Combiner.CombiningCallable;
import com.google.common.util.concurrent.Futures.FutureCombiner;
import com.google.errorprone.annotations.CanIgnoreReturnValue;