}

    private void getDownstreamProjects(String projectId, Set<String> projectIds, boolean transitive) {
        for (String id : sorter.getDependents(projectId)) {
            if (projectIds.add(id) && transitive) {
                getDownstreamProjects(id, projectIds, transitive);
            }
        }
    }

    public List<MavenProject> getUpstreamProjects(MavenProject project, boolean transitive) {

            String id = repo.getId();

            if (id == null || id.isEmpty()) {
                throw new InvalidRepositoryException("Repository identifier missing", "");
            }

            String url = repo.getUrl();

            if (url == null || url.isEmpty()) {
                throw new InvalidRepositoryException("URL missing for repository " + id, id);
            }

    <!-- Site omitted - each project must provide their own -->
    <repository>
      <id>apache.releases</id>
      <name>Apache Release Distribution Repository</name>
      <url>scp://people.apache.org/www/people.apache.org/repo/m2-ibiblio-rsync-repository</url>
    </repository>
    <snapshotRepository>
      <id>apache.snapshots</id>
      <name>Apache Development Snapshot Repository</name>

    </mailingList>
  </mailingLists>

  <distributionManagement>
    <repository>
      <id>repo1</id>
      <name>Maven Central Repository</name>
      <url>scp://repo1.maven.org/home/projects/maven/repository-staging/to-ibiblio/maven2</url>
    </repository>
    <snapshotRepository>
      <id>snapshots</id>
      <name>Maven Central Development Repository</name>

    </mailingList>
  </mailingLists>

  <developers>
    <developer>
      <id>jvanzyl</id>
      <name>Jason van Zyl</name>
      <email>******@****.***</email>
      <organization>ASF</organization>
      <roles>
        <role>PMC Chair</role>
      </roles>
      <timezone>-5</timezone>
    </developer>
    <developer>
      <id>brett</id>
      <name>Brett Porter</name>
      <email>******@****.***</email>

    }

    private ArtifactSpec createArtifactSpec(String id, String version) throws InvalidVersionSpecificationException {
        return createArtifactSpec(id, version, Artifact.SCOPE_COMPILE);
    }

    private ArtifactSpec createArtifactSpec(String id, String version, boolean optional)
            throws InvalidVersionSpecificationException {
        return createArtifactSpec(id, version, Artifact.SCOPE_COMPILE, null, optional);
    }

     * @return the current offset
     */
    int getCharacterOffset();

    /**
     * Returns the public ID of the XML
     * @return the public ID, or null if not available
     */
    String getPublicId();

    /**
     * Returns the system ID of the XML
     * @return the system ID, or null if not available
     */
    String getSystemId();

    </mailingList>
  </mailingLists>
  <developers>
    <developer>
      <id>jvanzyl</id>
      <name>Jason van Zyl</name>
      <email>******@****.***</email>
      <organization>ASF</organization>
      <roles>
        <role>PMC Chair</role>
      </roles>
      <timezone>-5</timezone>
    </developer>
    <developer>
      <id>brett</id>
      <name>Brett Porter</name>
      <email>******@****.***</email>

                "'profiles.profile[pro].repositories.repository.id' must be unique"
                        + " but found duplicate repository with id test");
    }

    @Test
    void testValidateUniqueProxyId() throws Exception {
        Settings settings = new Settings();
        Proxy proxy = new Proxy();
        String id = "foo";
        proxy.setId(id);
        proxy.setHost("www.example.com");

          </configuration>
          <executions>
            <execution>
              <id>site-docs</id>
              <phase>pre-site</phase>
              <goals>
                <goal>xdoc</goal>
                <goal>xsd</goal>
              </goals>
            </execution>
            <execution>
              <id>standard</id>
              <goals>
                <goal>java</goal>