* only the entries for {@code keys} will be returned from {@code getAll}.
   *
   * <p>This method should be overridden when bulk retrieval is significantly more efficient than
   * many individual lookups. Note that {@link LoadingCache#getAll} will defer to individual calls
   * to {@link LoadingCache#get} if this method is not overridden.
   *
   * @param keys the unique, non-null keys whose values should be loaded

   * only the entries for {@code keys} will be returned from {@code getAll}.
   *
   * <p>This method should be overridden when bulk retrieval is significantly more efficient than
   * many individual lookups. Note that {@link LoadingCache#getAll} will defer to individual calls
   * to {@link LoadingCache#get} if this method is not overridden.
   *
   * @param keys the unique, non-null keys whose values should be loaded

 *
 * <p>An {@code Escaper} instance is required to be stateless, and safe when used concurrently by
 * multiple threads.
 *
 * <p>Because, in general, escaping operates on the code points of a string and not on its
 * individual {@code char} values, it is not safe to assume that {@code escape(s)} is equivalent to
 * {@code escape(s.substring(0, n)) + escape(s.substring(n))} for arbitrary {@code n}. This is

   */
  public void addAll(long... values) {
    for (long value : values) {
      add(value);
    }
  }

  /**
   * Adds the given statistics to the dataset, as if the individual values used to compute the
   * statistics had been added directly.
   */
  public void addAll(Stats values) {
    if (values.count() == 0) {
      return;
    }

   * not necessarily a {@link SortedMap}: A {@code SortedSetMultimap} must expose the <i>values</i>
   * for a given key in sorted order, but it need not expose the <i>keys</i> in sorted order.
   * Individual {@code SortedSetMultimap} implementations, like those built with {@link
   * MultimapBuilder#treeKeys()}, may make additional guarantees.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**

       * a NoClassDefFoundError. Other apps might deny access to sun.misc packages.
       */
      return null;
    }
  }

  /**
   * Returns the Method that can be used to resolve an individual StackTraceElement, or null if that
   * method cannot be found (it is only to be found in fairly recent JDKs).
   */
  @J2ktIncompatible
  @GwtIncompatible // java.lang.reflect
  @CheckForNull

 * additional configuration, permits will be distributed at a fixed rate, defined in terms of
 * permits per second. Permits will be distributed smoothly, with the delay between individual
 * permits being adjusted to ensure that the configured rate is maintained.
 *
 * <p>It is possible to configure a {@code RateLimiter} to have a warmup period during which time

       * a NoClassDefFoundError. Other apps might deny access to sun.misc packages.
       */
      return null;
    }
  }

  /**
   * Returns the Method that can be used to resolve an individual StackTraceElement, or null if that
   * method cannot be found (it is only to be found in fairly recent JDKs).
   */
  @J2ktIncompatible
  @GwtIncompatible // java.lang.reflect
  @CheckForNull

   * the result set is constructed, the input set is merely copied. Only as the result set is
   * iterated are the individual subsets created. Each of these subsets occupies an additional O(n)
   * memory but only for as long as the user retains a reference to it. That is, the set returned by
   * {@code combinations} does not retain the individual subsets.
   *
   * @param set the set of elements to take combinations of

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A future whose value is derived from a collection of input futures.
 *
 * @param <InputT> the type of the individual inputs
 * @param <OutputT> the type of the output (i.e. this) future
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AggregateFuture<InputT extends @Nullable Object, OutputT extends @Nullable Object>