}
      }
    }
  }

  public void testToArray_withNull() {
    List<@Nullable Double> list = Arrays.asList(0.0, 1.0, null);
    assertThrows(NullPointerException.class, () -> Doubles.toArray(list));
  }

  public void testToArray_withConversion() {
    double[] array = {0.0, 1.0, 2.0};

    List<Byte> bytes = Arrays.asList((byte) 0, (byte) 1, (byte) 2);

    return asImmutableList(array);
  }

  private static <E> List<E> nullCheckedList(Object... array) {
    for (int i = 0, len = array.length; i < len; i++) {
      if (array[i] == null) {
        throw new NullPointerException("at index " + i);
      }
    }
    @SuppressWarnings("unchecked")
    E[] castedArray = (E[]) array;
    return Arrays.asList(castedArray);
  }

  @Override

  }

  /**
   * Creates a new {@code AtomicDoubleArray} with the same length as, and all elements copied from,
   * the given array.
   *
   * @param array the array to copy elements from
   * @throws NullPointerException if array is null
   */
  public AtomicDoubleArray(double[] array) {
    int len = array.length;
    long[] longArray = new long[len];
    for (int i = 0; i < len; i++) {

   * possible.
   *
   * @param sources the sources to concatenate
   * @return a {@code CharSource} containing the concatenated data
   * @throws NullPointerException if any of {@code sources} is {@code null}
   * @since 15.0
   */
  public static CharSource concat(Iterator<? extends CharSource> sources) {
    return concat(ImmutableList.copyOf(sources));
  }

  /**

   *
   * @param collection a collection of {@code Character} objects
   * @return an array containing the same values as {@code collection}, in the same order, converted
   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   */
  public static char[] toArray(Collection<Character> collection) {
    if (collection instanceof CharArrayAsList) {

   *
   * @param collection a collection of {@code Number} instances
   * @return an array containing the same values as {@code collection}, in the same order, converted
   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   * @since 1.0 (parameter was {@code Collection<Short>} before 12.0)
   */
  public static short[] toArray(Collection<? extends Number> collection) {

        }
      }
    }
  }

  public void testToArray_withNull() {
    List<@Nullable Integer> list = Arrays.asList((int) 0, (int) 1, null);
    assertThrows(NullPointerException.class, () -> Ints.toArray(list));
  }

  public void testToArray_withConversion() {
    int[] array = {0, 1, 2};

    List<Byte> bytes = Arrays.asList((byte) 0, (byte) 1, (byte) 2);

   * possible.
   *
   * @param sources the sources to concatenate
   * @return a {@code CharSource} containing the concatenated data
   * @throws NullPointerException if any of {@code sources} is {@code null}
   * @since 15.0
   */
  public static CharSource concat(Iterator<? extends CharSource> sources) {
    return concat(ImmutableList.copyOf(sources));
  }

  /**

   *
   * @param collection a collection of {@code Number} instances
   * @return an array containing the same values as {@code collection}, in the same order, converted
   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   * @since 1.0 (parameter was {@code Collection<Short>} before 12.0)
   */
  public static short[] toArray(Collection<? extends Number> collection) {

   *
   * <ul>
   *   <li>The {@link Predicate} returned by this method is {@link Serializable}.
   *   <li>The {@link Predicate} returned by this method catches {@link ClassCastException} and
   *       {@link NullPointerException}.
   *   <li>Code that chains multiple predicates together (especially negations) may be more readable
   *       using this method. For example, {@code not(in(target))} is generally more readable than