*
 * <ul>
 *   <li>does not allow parallel edges
 *   <li>does not allow self-loops
 *   <li>orders {@link Network#nodes()} and {@link Network#edges()} in the order in which the
 *       elements were added (insertion order)
 * </ul>
 *
 * <p>{@code Network}s built by this class also guarantee that each collection-returning accessor
 * returns a <b>(live) unmodifiable view</b>; see <a

      @CompatibleWith("V") @CheckForNull Object value);

  // Modification Operations

  /**
   * Stores a key-value pair in this multimap.
   *
   * <p>Some multimap implementations allow duplicate key-value pairs, in which case {@code put}
   * always adds a new key-value pair and increases the multimap size by 1. Other implementations

 *
 * <p>The classes in this package include:
 *
 * <h2>Immutable collections</h2>
 *
 * These are collections whose contents will never change. They also offer a few additional
 * guarantees (see {@link ImmutableCollection} for details). Implementations are available for both
 * the JDK collection types and the Guava collection types (listed below).
 *
 * <h2>Collection types</h2>

   * printing space backward on the same printing line. (Applicable also to display devices.)
   *
   * @since 8.0
   */
  public static final byte BS = 8;

  /**
   * Horizontal Tabulation ('\t'): A format effector which controls the movement of the printing
   * position to the next in a series of predetermined positions along the printing line.
   * (Applicable also to display devices and the skip function on punched cards.)
   *

   * the discussion in the {@link #addListener} documentation. All its warnings about heavyweight
   * listeners are also applicable to heavyweight functions passed to this method.
   *
   * <p>This method is similar to {@link java.util.concurrent.CompletableFuture#exceptionally}. It
   * can also serve some of the use cases of {@link java.util.concurrent.CompletableFuture#handle}

 * associated with a key and then add the key back to the multimap, that key will come last in the
 * key iteration order.
 *
 * <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.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *

        long aHi = a >>> 32; // < 2^31
        long bHi = b >>> 32; // < 2^31
        long aLo = a & 0xFFFFFFFFL; // < 2^32
        long bLo = b & 0xFFFFFFFFL; // < 2^32

        /*
         * a * b == aHi * bHi * 2^64 + (aHi * bLo + aLo * bHi) * 2^32 + aLo * bLo.
         *       == (aHi * bHi * 2^32 + aHi * bLo + aLo * bHi) * 2^32 + aLo * bLo
         *

      int n, @Nullable Object[] alternatingKeysAndValues) {
    return create(n, alternatingKeysAndValues, /* builder= */ null);
  }

  // This entry point is used by the other create method but also directly by
  // ImmutableMap.Builder, so that it can remember any DuplicateKey encountered and produce an
  // exception for a later buildOrThrow(). If builder is null that means that a duplicate

 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedListMultimap}.
 *

     how to go about it.
  2. All contributions must be licensed Apache 2.0 and all files must have a
     copy of the boilerplate license comment (can be copied from an existing
     file).
  3. Files should be formatted according to Google's [Java style guide][].
  4. Please squash all commits for a change into a single commit (this can be