* note that the execution order of all listeners is ultimately chosen by the implementations of
   * the supplied executors.
   *
   * <p>This method is idempotent. Calling it several times in parallel is semantically equivalent
   * to calling it exactly once.
   *
   * @since 10.0 (present in 1.0 as {@code run})
   */
  public void execute() {

   *     can <i>usually</i> still preserve behavior by passing an explicit {@code null} cause. Note,
   *     however, that passing an explicit {@code null} cause prevents anyone from calling {@link
   *     #initCause} later, so it is not quite equivalent to using a constructor that omits the
   *     cause.
   */
  @Deprecated
  protected ExecutionError() {}

  /**

   * value that are {@linkplain Range#isConnected connected} to this range.
   *
   * <p>The behavior of {@link #get(Comparable) get(k)} after calling this method is identical to
   * the behavior described in {@link #put(Range, Object) put(range, value)}, however the ranges
   * returned from {@link #asMapOfRanges} will be different if there were existing entries which

        return new ImmutableEnumSet<>(set);
    }
  }

  /*
   * Notes on EnumSet and <E extends Enum<E>>:
   *
   * This class isn't an arbitrary ForwardingImmutableSet because we need to
   * know that calling {@code clone()} during deserialization will return an
   * object that no one else has a reference to, allowing us to guarantee
   * immutability. Hence, we support only {@link EnumSet}.
   */

  public static boolean equal(@CheckForNull Object a, @CheckForNull Object b) {
    return a == b || (a != null && a.equals(b));
  }

  /**
   * Generates a hash code for multiple values. The hash code is generated by calling {@link
   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.

  public static boolean equal(@CheckForNull Object a, @CheckForNull Object b) {
    return a == b || (a != null && a.equals(b));
  }

  /**
   * Generates a hash code for multiple values. The hash code is generated by calling {@link
   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.

        | ((source[offset + 3] & 0xFF) << 24);
  }

  /**
   * Indicates that the loading of Unsafe was successful and the load and store operations will be
   * very efficient. May be useful for calling code to fall back on an alternative implementation
   * that is slower than Unsafe.get/store but faster than the pure-Java mask-and-shift.
   */
  static boolean usingUnsafe() {

import java.util.concurrent.RejectedExecutionException;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/** Aggregate future that computes its value by calling a callable. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class CombinedFuture<V extends @Nullable Object>
    extends AggregateFuture<@Nullable Object, V> {

      }

      @Override
      public boolean remove(@CheckForNull Object o) {
        throw new UnsupportedOperationException();
      }

      // Mostly safe: We check contains(u) before calling successors(u), so we perform unsafe
      // operations only in weird cases like checking for an EndpointPair<ArrayList> in a
      // Graph<LinkedList>.
      @SuppressWarnings("unchecked")
      @Override

          + "so it cannot be reused to connect the following nodes: %s.";
  static final String MULTIPLE_EDGES_CONNECTING =
      "Cannot call edgeConnecting() when parallel edges exist between %s and %s. Consider calling "
          + "edgesConnecting() instead.";
  static final String PARALLEL_EDGES_NOT_ALLOWED =
      "Nodes %s and %s are already connected by a different edge. To construct a graph "