}

    private void getReadyToExpandTo(int minCapacity) {
      if (contents.length < minCapacity) {
        this.contents = Arrays.copyOf(contents, expandedCapacity(contents.length, minCapacity));
        forceCopy = false;
      } else if (forceCopy) {
        contents = Arrays.copyOf(contents, contents.length);
        forceCopy = false;
      }
    }

    /**

    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;
    }