* ImmutableList#builder}.
     */
    public Builder() {
      this(DEFAULT_INITIAL_CAPACITY);
    }

    Builder(int capacity) {
      this.contents = new @Nullable Object[capacity];
      this.size = 0;
    }

    private void getReadyToExpandTo(int minCapacity) {
      if (contents.length < minCapacity) {

    private final ArrayList<E> contents;

    public Builder() {
      contents = Lists.newArrayList();
    }

    Builder(int capacity) {
      contents = Lists.newArrayListWithCapacity(capacity);
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E element) {
      contents.add(checkNotNull(element));
      return this;
    }

     * ImmutableList#builder}.
     */
    public Builder() {
      this(DEFAULT_INITIAL_CAPACITY);
    }

    Builder(int capacity) {
      super(capacity);
    }

    /**
     * Adds {@code element} to the {@code ImmutableList}.
     *
     * @param element the element to add
     * @return this {@code Builder} object