}

    @Override
    public Model findModel(Artifact artifact) {
        if (GROUP_ID.equals(artifact.getGroupId())
                && ARTIFACT_ID.equals(artifact.getArtifactId())
                && VERSION.equals(artifact.getVersion())) {
            Model m = new Model();
            m.setArtifactId(ARTIFACT_ID);
            m.setGroupId(GROUP_ID);
            m.setVersion(VERSION);
            Repository repository = new Repository();

<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <groupId>org.apache.maven.its</groupId>
  <artifactId>a</artifactId>
  <version>0.1</version>
  <versioning>
    <versions>
      <version>0.1</version>
    </versions>
    <lastUpdated>20091023222756</lastUpdated>
  </versioning>

<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <groupId>org.apache.maven.its</groupId>
  <artifactId>a</artifactId>
  <version>0.1</version>
  <versioning>
    <versions>
      <version>0.1</version>
    </versions>
    <lastUpdated>20091023222756</lastUpdated>
  </versioning>

  <parent>
    <groupId>org.apache.maven</groupId>
    <artifactId>maven-api</artifactId>
    <version>4.1.0-SNAPSHOT</version>
  </parent>

  <artifactId>maven-api-xml</artifactId>
  <name>Maven 4 API :: XML</name>
  <description>Maven 4 API - Immutable XML.</description>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-annotations</artifactId>

                        final SID groupSid = new SID(domSid, entry.idx);
                        groupSid.type = jcifs.SID.SID_TYPE_ALIAS;
                        groupSid.domainName = domSid.getDomainName();
                        groupSid.acctName = new UnicodeString(entry.name, false).toString();

                        for (final SID mem : mems) {

            }
        }
        return this;
    }

    private Plugin findPlugin(Model model, String groupId, String artifactId) {
        if (Objects.requireNonNull(groupId, "groupId cannot be null").isEmpty()) {
            throw new IllegalArgumentException("groupId cannot be empty");
        }
        if (Objects.requireNonNull(artifactId, "artifactId cannot be null").isEmpty()) {

     * @param data The data to store in the cache, must not be {@code null}.
     */
    void put(String groupId, String artifactId, String version, String tag, Object data);

    /**
     * Gets the specified data from the cache.
     *
     * @param groupId The group id of the cache record, must not be {@code null}.
     * @param artifactId The artifact id of the cache record, must not be {@code null}.

    @Override
    public Artifact createArtifact(String groupId, String artifactId, String version, String scope, String type) {
        return artifactFactory.createArtifact(groupId, artifactId, version, scope, type);
    }

    @Override
    public Artifact createArtifact(String groupId, String artifactId, String version, String packaging) {
        return artifactFactory.createBuildArtifact(groupId, artifactId, version, packaging);
    }

  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.apache.maven.validation</groupId>
    <artifactId>parent</artifactId>
    <version>1</version>
  </parent>

  <groupId>org.apache.maven.validation</groupId>
  <artifactId>project</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <repositories>
    <repository>
      <id>repo</id>

    }

    @Test
    void testMissingGroupId() throws Exception {
        SimpleProblemCollector result = validate("missing-groupId-pom.xml");

        assertViolations(result, 0, 1, 0);

        assertEquals("'groupId' is missing.", result.getErrors().get(0));
    }

    @Test
    void testInvalidCoordinateIds() throws Exception {