* the <code>Mojo</code> to communicate errors.
     *
     * @throws MojoExecutionException if an unexpected problem occurs.
     * Throwing this exception causes a "BUILD ERROR" message to be displayed.
     * @throws MojoFailureException if an expected problem (such as a compilation failure) occurs.
     * Throwing this exception causes a "BUILD FAILURE" message to be displayed.
     */

     * and child directory == artifactId
     * @throws IOException Model read problem
     */
    @Test
    void testUrls() throws Exception {
        testInheritance("urls");
    }

    /**
     * Flat directory structure: parent & child POMs in sibling directories, child directory == artifactId.
     * @throws IOException Model read problem
     */
    @Test
    void testFlatUrls() throws IOException {

     *
     * @param model the input model
     * @param problems the problem collector to report any issues encountered during transformation
     * @return the transformed model, or the input model if no transformation is needed
     */
    @Nonnull
    Model transform(
            @Nonnull Model model, @Nonnull ModelBuilderRequest request, @Nonnull ModelProblemCollector problems);

   * A word about using {@link Equivalence}, which automatically checks for {@code null} and
   * identical inputs: This sounds like it ought to be a problem here, since the goals of this class
   * include testing that {@code equals()} is reflexive and is tolerant of {@code null}. However,
   * there's no problem. The reason: {@link EqualsTester} tests {@code null} and identical inputs
   * directly against {@code equals()} rather than through the {@code Equivalence}.

  }

  private static class StringWrapper {
    private final String value;

    StringWrapper(String value) {
      this.value = value;
    }
  }

  @GwtIncompatible // J2CL generics problem
  public void testAndThen() {
    Converter<StringWrapper, String> first =
        new Converter<StringWrapper, String>() {
          @Override
          protected String doForward(StringWrapper object) {

   * nullness analysis might not understand that the field has been populated. To avoid that problem
   * without having to add {@code @SuppressWarnings}, the code can call this method.
   *
   * <p>Why <i>not</i> just add {@code SuppressWarnings}? The problem is that this method is
   * typically useful for {@code return} statements. That leaves the code with two options: Either

   * nullness analysis might not understand that the field has been populated. To avoid that problem
   * without having to add {@code @SuppressWarnings}, the code can call this method.
   *
   * <p>Why <i>not</i> just add {@code SuppressWarnings}? The problem is that this method is
   * typically useful for {@code return} statements. That leaves the code with two options: Either

</source>

<!--
    We used to set this only for packages that had manual supersource. That
    worked everywhere that I know of except for one place: when running the GWT
    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see
    https://groups.google.com/g/google-web-toolkit-contributors/c/CqYH59Dt_rQ/m/uVGW1QdUsXUJ
    for details.

    /**
     * The default implementation is not visible, create it with this factory
     *
     * @param problems starting set of problems, may be {@code null}
     * @return a new instance of a ProblemCollector
     */
    public static ProblemCollector newInstance(List<Problem> problems) {
        return new DefaultProblemCollector(problems);
    }

   * reading, such as an {@code InputStream}. Unlike with writable resources, there's no chance that
   * a failure that occurs when closing the stream indicates a meaningful problem such as a failure
   * to flush all bytes to the underlying resource.
   *
   * @param inputStream the input stream to be closed, or {@code null} in which case this method
   *     does nothing
   * @since 17.0