Element candidate = newElement();
      if (!elementsInSet.contains(candidate)) {
        queryList.add(candidate);
      }
    }
    shuffle(queryList, random);
    return queryList.toArray(new Element[0]);
  }

  private Set<Element> createData() {
    Set<Element> set = Sets.newHashSetWithExpectedSize(size);
    while (set.size() < size) {
      set.add(newElement());
    }
    return set;
  }

      Element candidate = newElement();
      if (!elementsInSet.contains(candidate)) {
        queryList.add(candidate);
      }
    }
    shuffle(queryList, random);
    return queryList.toArray(new Element[0]);
  }

  private Set<Element> createData() {
    Set<Element> set = Sets.newHashSetWithExpectedSize(size);
    while (set.size() < size) {
      set.add(newElement());
    }
    return set;
  }

     * current array, create a new array.
     */
    private void ensureRoomFor(int newElements) {
      @Nullable Object[] contents = this.contents;
      int newCapacity = expandedCapacity(contents.length, size + newElements);
      // expandedCapacity handles the overflow case
      if (newCapacity > contents.length || forceCopy) {

  }

  @Override
  public final boolean remove(@Nullable Object object) {
    throw new UnsupportedOperationException();
  }

  @Override
  public final boolean addAll(Collection<? extends E> newElements) {
    throw new UnsupportedOperationException();
  }

  @Override
  public final boolean removeAll(Collection<?> oldElements) {
    throw new UnsupportedOperationException();
  }

  @Override

  public int lastIndexOf(@Nullable Object object) {
    return (object == null) ? -1 : Lists.lastIndexOfImpl(this, object);
  }

  @Override
  public final boolean addAll(int index, Collection<? extends E> newElements) {
    throw new UnsupportedOperationException();
  }

  @Override
  public final E set(int index, E element) {
    throw new UnsupportedOperationException();
  }

  @Override

   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final boolean addAll(int index, Collection<? extends E> newElements) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the list unmodified.
   *
   * @throws UnsupportedOperationException always

   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final boolean addAll(Collection<? extends E> newElements) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the collection unmodified.
   *
   * @throws UnsupportedOperationException always

     */
    @CanIgnoreReturnValue
    @Deprecated
    @Override
    @DoNotCall("Always throws UnsupportedOperationException")
    public final boolean addAll(Collection<? extends E> newElements) {
      throw new UnsupportedOperationException();
    }

    /**
     * Guaranteed to throw an exception and leave the collection unmodified.
     *
     * @throws UnsupportedOperationException always