*/
    @Nonnull
    ArtifactCoordinates createArtifactCoordinates(String groupId, String artifactId, String version, String extension);

    /**
     * Shortcut for {@code getService(ArtifactFactory.class).create(...)}.
     *
     * @param groupId the group identifier, or {@code null} is unspecified
     * @param artifactId the artifact identifier, or {@code null} is unspecified

    public ModelSource resolveModel(String groupId, String artifactId, String version)
            throws UnresolvableModelException {
        File pomFile = null;

        if (modelPool != null) {
            pomFile = modelPool.get(groupId, artifactId, version);
        }

        if (pomFile == null) {
            Artifact pomArtifact = new DefaultArtifact(groupId, artifactId, "", "pom", version);

            try {

  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>inheritance</groupId>
  <artifactId>empty</artifactId>
  <version>1</version>
  <modules>
    <module>child</module>
  </modules>
  <url></url>
  <scm>
    <connection> </connection>
    <developerConnection>  </developerConnection>
    <url></url>

  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.example.group</groupId>
  <artifactId>valid-version-sha1</artifactId>
  <version>${revision}${changelist}${sha1}</version>

  <description>
    This will test if the validation for the ci friendly versions
    is working correct.
  </description>

specific language governing permissions and limitations
under the License.
-->

<project>
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.apache.maven.its.mng3906</groupId>
  <artifactId>a</artifactId>
  <version>0.1</version>
  <packaging>jar</packaging>

  <distributionManagement>
    <repository>
      <id>maven-core-it</id>
      <url>file:///${basedir}/repo</url>
    </repository>

specific language governing permissions and limitations
under the License.
-->

<project>
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.apache.maven.its.mng3906</groupId>
  <artifactId>a</artifactId>
  <version>0.2</version>
  <packaging>jar</packaging>

  <distributionManagement>
    <repository>
      <id>maven-core-it</id>
      <url>file:///${basedir}/repo</url>
    </repository>

specific language governing permissions and limitations
under the License.
-->

<project>
  <modelVersion>99.0.0</modelVersion>
  <groupId>foo</groupId>
  <artifactId>bar</artifactId>
  <version>0.1</version>

specific language governing permissions and limitations
under the License.
-->

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>foo</groupId>
  <artifactId>bar</artifactId>
  <version>this\is/bad</version>

specific language governing permissions and limitations
under the License.
-->

<project>
  <modelVersion>4.0</modelVersion>
  <groupId>foo</groupId>
  <artifactId>bar</artifactId>
  <version>0.1</version>

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>
  <artifactId>aid</artifactId>
  <groupId>gid</groupId>
  <version>0.1</version>
  <packaging>pom</packaging>

  <profiles>

    <profile>
      <id>exists-project-version</id>
      <activation>
        <file>