this.locks = new AtomicReferenceArray<>(size);
      this.supplier = supplier;
    }

    @Override
    public L getAt(int index) {
      if (size != Integer.MAX_VALUE) {
        Preconditions.checkElementIndex(index, size());
      } // else no check necessary, all index values are valid
      ArrayReference<? extends L> existingRef = locks.get(index);
      L existing = existingRef == null ? null : existingRef.get();

   *
   * @throws IndexOutOfBoundsException if {@code index} is negative, or greater than or equal to
   *     {@link #length}
   */
  public long get(int index) {
    Preconditions.checkElementIndex(index, length());
    return array[start + index];
  }

  /**
   * Returns the smallest index for which {@link #get} returns {@code target}, or {@code -1} if no

   *
   * @throws IndexOutOfBoundsException if {@code index} is negative, or greater than or equal to
   *     {@link #length}
   */
  public double get(int index) {
    Preconditions.checkElementIndex(index, length());
    return array[start + index];
  }

  /**
   * Returns the smallest index for which {@link #get} returns {@code target}, or {@code -1} if no

   *
   * @throws IndexOutOfBoundsException if {@code index} is negative, or greater than or equal to
   *     {@link #length}
   */
  public int get(int index) {
    Preconditions.checkElementIndex(index, length());
    return array[start + index];
  }

  /**
   * Returns the smallest index for which {@link #get} returns {@code target}, or {@code -1} if no