* family. <b>Avoid</b> creating a mock or stub {@code Future}. Mock and stub implementations are
 * fragile because they assume that only certain methods will be called and because they often
 * implement subtleties of the API improperly.
 *
 * <p><b>Custom implementation</b>: Avoid implementing {@code ListenableFuture} from scratch. If you
 * can't get by with the standard implementations, prefer to derive a new {@code Future} instance

   * any {@code Entry} instances already retrieved from the entry set (this is
   * implementation-dependent). Furthermore, implementations are not required to support
   * modifications to the entry set at all, and the {@code Entry} instances themselves don't even
   * have methods for modification. See the specific implementation class for more details on how
   * its entry set handles modifications.
   *

import static java.util.Objects.requireNonNull;

import com.google.common.collect.ImmutableList;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import javax.annotation.CheckForNull;

/**
 * Standard implementation of {@link MutableValueGraph} that supports both directed and undirected
 * graphs. Instances of this class should be constructed with {@link ValueGraphBuilder}.
 *

import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import javax.annotation.CheckForNull;

/**
 * Standard implementation of {@link ValueGraph} that supports the options supplied by {@link
 * AbstractGraphBuilder}.
 *
 * <p>This class maintains a map of nodes to {@link GraphConnections}.
 *

import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of {@link Multimap} using hash tables.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *

 * natural order or an explicit {@link Comparator}. This order is reflected when iterating over the
 * sorted multiset, either directly, or through its {@code elementSet} or {@code entrySet} views. In
 * all cases, this implementation uses {@link Comparable#compareTo} or {@link Comparator#compare}
 * instead of {@link Object#equals} to determine equivalence of instances.
 *

 * natural order or an explicit {@link Comparator}. This order is reflected when iterating over the
 * sorted multiset, either directly, or through its {@code elementSet} or {@code entrySet} views. In
 * all cases, this implementation uses {@link Comparable#compareTo} or {@link Comparator#compare}
 * instead of {@link Object#equals} to determine equivalence of instances.
 *

import static java.util.Objects.requireNonNull;

import com.google.common.collect.ImmutableList;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import javax.annotation.CheckForNull;

/**
 * Standard implementation of {@link MutableValueGraph} that supports both directed and undirected
 * graphs. Instances of this class should be constructed with {@link ValueGraphBuilder}.
 *

 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@code Multiset} implementation with predictable iteration order. Its iterator orders elements
 * according to when the first occurrence of the element was added. When the multiset contains

   * containers with a known order other than insertion order must override this method.
   *
   * <p>Note: This default implementation is overkill (but valid) for an unordered container. An
   * equally valid implementation for an unordered container is to throw an exception. The chosen
   * implementation, however, has the advantage of working for insertion-ordered containers, as
   * well.
   */
  @Override