// 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
   * prohibit duplicates, and storing a key-value pair that's already in the multimap has no effect.
   *

    // Identical valid surrogate pairs.
    assertEquals(
        "abc\uD8AB\uDCAB", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz"));
    // Differing valid surrogate pairs.
    assertEquals("abc", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCACxyz"));
    // One invalid pair.
    assertEquals("abc", Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uD8ABxyz"));

     * soon be deprecated.
     *
     * @throws IllegalArgumentException if duplicate key pairs were added
     */
    public ImmutableTable<R, C, V> build() {
      return buildOrThrow();
    }

    /**
     * Returns a newly-created immutable table, or throws an exception if duplicate key pairs were
     * added.
     *

     * soon be deprecated.
     *
     * @throws IllegalArgumentException if duplicate key pairs were added
     */
    public ImmutableTable<R, C, V> build() {
      return buildOrThrow();
    }

    /**
     * Returns a newly-created immutable table, or throws an exception if duplicate key pairs were
     * added.
     *

      Comparator<Entry<K, V>> entryComparator(@Nullable Comparator<? super K> keyComparator) {
    return new EntryComparator<K, V>(keyComparator);
  }

  /**
   * Asserts that all pairs of {@code T} values within {@code valuesInExpectedOrder} are ordered
   * consistently between their order within {@code valuesInExpectedOrder} and the order implied by
   * the given {@code comparator}.
   *

 * 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.
 *

    return new String(array);
  }

  /**
   * Returns the longest string {@code prefix} such that {@code a.toString().startsWith(prefix) &&
   * b.toString().startsWith(prefix)}, taking care not to split surrogate pairs. If {@code a} and
   * {@code b} have no common prefix, returns the empty string.
   *
   * @since 11.0
   */
  public static String commonPrefix(CharSequence a, CharSequence b) {
    checkNotNull(a);

     * The configuration string format is "clientName:pattern,clientName:pattern,..."
     * Results are cached to improve performance on subsequent calls.
     *
     * @param value the client rule configuration string
     * @return a list of pairs containing client names and their corresponding compiled patterns
     */

  }

  @LazyInit @RetainedWith private transient @Nullable ImmutableSetMultimap<V, K> inverse;

  /**
   * {@inheritDoc}
   *
   * <p>Because an inverse of a set multimap cannot contain multiple pairs with the same key and
   * value, this method returns an {@code ImmutableSetMultimap} rather than the {@code
   * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
   */
  @Override

 * difference. A CharEscaper can only process Java <a
 * href="http://en.wikipedia.org/wiki/UTF-16">UTF16</a> characters in isolation and may not cope
 * when it encounters surrogate pairs. This class facilitates the correct escaping of all Unicode
 * characters.
 *
 * <p>As there are important reasons, including potential security issues, to handle Unicode