return false; // This is the first occurrence
                    }
                })
                .toList();

        // Remove duplicates while preserving formatting
        duplicates.forEach(DomUtils::removeElement);

        return !duplicates.isEmpty();
    }

    private String createDependencyKey(Element dependency) {
        String groupId = dependency.childText(MavenPomElements.Elements.GROUP_ID);

    }

    /**
     * Gets the maximum number of duplicated paths to attempt.
     *
     * @return the maximum duplicated path count
     */
    public int getMaxDuplicatedPath() {
        return maxDuplicatedPath;
    }

    /**
     * Sets the maximum number of duplicated paths to attempt.
     *
     * @param maxDuplicatedPath the maximum duplicated path count to set
     */

    }

    @Override
    public Set<E> create(Object... elements) {
      Object[] duplicated = new Object[elements.length * 2];
      for (int i = 0; i < elements.length; i++) {
        duplicated[i] = elements[i];
        duplicated[i + elements.length] = elements[i];
      }
      return ((Multiset<E>) gen.create(duplicated)).elementSet();
    }

    @Override
    public E[] createArray(int length) {

    }

    @Override
    public Set<E> create(Object... elements) {
      Object[] duplicated = new Object[elements.length * 2];
      for (int i = 0; i < elements.length; i++) {
        duplicated[i] = elements[i];
        duplicated[i + elements.length] = elements[i];
      }
      return ((Multiset<E>) gen.create(duplicated)).elementSet();
    }

    @Override
    public E[] createArray(int length) {

    @SuppressWarnings("unchecked")
    E[] array = (E[]) elements.toArray();
    /*
     * For a Set, we guess that it contains no duplicates. That's just a guess for purpose of
     * sizing; if the Set uses different equality semantics, it might contain duplicates according
     * to equals(), and we will deduplicate those properly, albeit at some cost in allocations.
     */
    int expectedSize =

     * we are trying to build. we assume a closed set.</li>
     * <li>do a topo sort on the graph that remains.</li>
     * </ul>
     * @throws DuplicateProjectException if any projects are duplicated by id
     */
    // MAVENAPI FIXME: the DAG used is NOT only used to represent the dependency relation,
    // but also for <parent>, <build><plugin>, <reports>. We need multiple DAG's

        assertEquals(cProject, sortedProjects.get(1));

        assertTrue(graph.getDownstreamProjects(aProject, false).contains(cProject));
    }

    // Test verifying that getDownstreamProjects does not contain duplicates.
    // This is a regression test for https://github.com/apache/maven/issues/2487.
    //
    // The graph is:
    // aProject -> bProject
    //        | -> dProject
    //        | -> eProject

        assertEquals("https://example.com/sitemap2.xml", sitemaps[1]);
    }

    public void test_addSitemapNoDuplicates() {
        // Test that addSitemap doesn't add duplicates
        RobotsTxt robotsTxt = new RobotsTxt();

        robotsTxt.addSitemap("https://example.com/sitemap.xml");
        robotsTxt.addSitemap("https://example.com/sitemap.xml");

     */
    public void setInitialBufferSize(final int initialBufferSize) {
        this.initialBufferSize = initialBufferSize;
    }

    /**
     * Sets whether duplicated terms are replaced.
     * @param replaceDuplication If true, duplicated terms are replaced.
     */
    public void setReplaceDuplication(final boolean replaceDuplication) {
        this.replaceDuplication = replaceDuplication;
    }

    /**

     * q-quantile.
     *
     * @param indexes the quantile indexes, each of which must be in the inclusive range [0, q] for
     *     q-quantiles; the order of the indexes is unimportant, duplicates will be ignored, and the
     *     set will be snapshotted when this method is called
     * @throws IllegalArgumentException if {@code indexes} is empty
     */
    public ScaleAndIndexes indexes(int... indexes) {