checkArgument(
        implementations.put(type, implementation) == null,
        "Implementation for %s was already registered",
        type);
  }

  static {
    setImplementation(Appendable.class, StringBuilder.class);
    setImplementation(BlockingQueue.class, LinkedBlockingDeque.class);
    setImplementation(BlockingDeque.class, LinkedBlockingDeque.class);
    setImplementation(ConcurrentMap.class, ConcurrentHashMap.class);

    String toTest =
        MoreObjects.toStringHelper(new TestClass())
            .omitEmptyValues()
            // CharSequences
            .add("field1", "")
            .add("field2", new StringBuilder())
            // nio CharBuffer (implements CharSequence) is tested separately below
            // Collections and Maps
            .add("field11", Arrays.asList("Hello"))
            .add("field12", new ArrayList<>())

  public void testIndexOf_genericPredicate() {
    List<CharSequence> sequences = Lists.newArrayList();
    sequences.add("bob");
    sequences.add(new StringBuilder("charlie"));
    sequences.add(new StringBuffer("henry"));
    sequences.add(new StringBuilder("apple"));
    sequences.add("lemon");

    assertEquals(3, Iterables.indexOf(sequences, STARTSWITH_A));
  }

        return string;
      }
      // if the length of the toString() result was > maxLength for some reason, truncate that
      seq = string;
    }

    return new StringBuilder(maxLength)
        .append(seq, 0, truncationLength)
        .append(truncationIndicator)
        .toString();
  }

  /**

    checkArgument(
        implementations.put(type, implementation) == null,
        "Implementation for %s was already registered",
        type);
  }

  static {
    setImplementation(Appendable.class, StringBuilder.class);
    setImplementation(BlockingQueue.class, LinkedBlockingDeque.class);
    setImplementation(BlockingDeque.class, LinkedBlockingDeque.class);
    setImplementation(ConcurrentMap.class, ConcurrentHashMap.class);

            Version version,
            String fieldName,
            String sourceHint,
            String message,
            InputLocationTracker tracker) {
        StringBuilder buffer = new StringBuilder(256);
        buffer.append('\'').append(fieldName).append('\'');

        if (sourceHint != null) {
            buffer.append(" for ").append(sourceHint);
        }

   * that this method will return a different number of chars than would be returned by reading all
   * of the chars.
   *
   * <p>Additionally, for mutable sources such as {@code StringBuilder}s, a subsequent read may
   * return a different number of chars if the contents are changed.
   *
   * @since 19.0
   */
  public Optional<Long> lengthIfKnown() {
    return Optional.absent();
  }

        return getDelegate().getProjectDirectory();
    }

    /**
     * @return the model id as {@code groupId:artifactId:packaging:version}
     */
    public String getId() {
        StringBuilder id = new StringBuilder( 64 );

        id.append( ( getGroupId() == null ) ? "[inherited]" : getGroupId() );
        id.append( ":" );
        id.append( getArtifactId() );
        id.append( ":" );

    internal var sequenceNumber: Long = 0

    init {
      // The names are repetitive so re-use the same builder to avoid allocations.
      val fileBuilder = StringBuilder(key).append('.')
      val truncateTo = fileBuilder.length
      for (i in 0 until valueCount) {
        fileBuilder.append(i)
        cleanFiles += directory / fileBuilder.toString()

    //   start->num => "num"     start->gap => "::"
    //   num->num   => ":num"    num->gap   => "::"
    //   gap->num   => "num"     gap->gap   => ""
    StringBuilder buf = new StringBuilder(39);
    boolean lastWasNumber = false;
    for (int i = 0; i < hextets.length; i++) {
      boolean thisIsNumber = hextets[i] >= 0;
      if (thisIsNumber) {
        if (lastWasNumber) {