@GwtCompatible(emulated = true)
public class SplitterTest extends TestCase {

  private static final Splitter COMMA_SPLITTER = Splitter.on(',');

  public void testSplitNullString() {
    assertThrows(NullPointerException.class, () -> COMMA_SPLITTER.split(null));
  }

  public void testCharacterSimpleSplit() {
    String simple = "a,b,c";
    Iterable<String> letters = COMMA_SPLITTER.split(simple);

     * such classes, this method always returns an empty string. But under some version of Java,
     * {@code class.getPackage().getName()} produces a {@code NullPointerException} because {@code
     * class.getPackage()} returns {@code null}.
     */
    public String getPackageName() {
      return Reflection.getPackageName(className);
    }

    /**

   *
   * @throws ClassCastException if the values are not mutually comparable
   * @throws NoSuchElementException if {@code values} is empty
   * @throws NullPointerException if any of {@code values} is null
   * @since 14.0
   */
  public static <C extends Comparable<?>> Range<C> encloseAll(Iterable<C> values) {
    checkNotNull(values);
    if (values instanceof SortedSet) {

  //             Thread.yield();
  //         }
  //     }

  public static class NPETask implements Callable<String> {
    @Override
    public String call() {
      throw new NullPointerException();
    }
  }

  public static class CallableOne implements Callable<Integer> {
    @Override
    public Integer call() {
      return one;
    }
  }

   *
   * <ul>
   *   <li>All non-private static methods are checked such that passing null for any parameter
   *       that's not annotated nullable should throw {@link NullPointerException}.
   *   <li>If there is any non-private constructor or non-private static factory method declared by
   *       {@code cls}, all non-private instance methods will be checked too using the instance

   * stream.
   *
   * <p>A caller can detect EOF if the number of bytes read is less than {@code len}. All subsequent
   * calls on the same stream will return zero.
   *
   * <p>If {@code b} is null, a {@code NullPointerException} is thrown. If {@code off} is negative,
   * or {@code len} is negative, or {@code off+len} is greater than the length of the array {@code

  //             Thread.yield();
  //         }
  //     }

  public static class NPETask implements Callable<String> {
    @Override
    public String call() {
      throw new NullPointerException();
    }
  }

  public static class CallableOne implements Callable<Integer> {
    @Override
    public Integer call() {
      return one;
    }
  }

   * returns a new {@code InternetDomainName} with the value {@code www.bar.foo.com}. Only lenient
   * validation is performed, as described {@link #from(String) here}.
   *
   * @throws NullPointerException if leftParts is null
   * @throws IllegalArgumentException if the resulting name is not valid
   */
  public InternetDomainName child(String leftParts) {
    return from(checkNotNull(leftParts) + "." + name);
  }

  }

  public void testConcatNullPointerException() {
    List<Integer> list1 = newArrayList(1);
    List<Integer> list2 = newArrayList(4);

    assertThrows(NullPointerException.class, () -> Iterables.concat(list1, null, list2));
  }

  public void testConcatPeformingFiniteCycle() {
    Iterable<Integer> iterable = asList(1, 2, 3);
    int n = 4;

       * more sense for us to fall back to a generic FileSystemException (by returning null here)
       * than to dereference parentPath and end up producing NullPointerException.
       */
      return null;
    }
    // requireNonNull is safe because paths have file names when they have parents.
    Path pathResolvedFromParent = parentPath.resolve(requireNonNull(path.getFileName()));