Best practice is to use the JIRA issue title in both the pull request title and in the first line of the commit message.
 - [ ] Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
 - [ ] Run `mvn clean verify` to make sure basic checks pass. A more thorough check will
       be performed on your pull request automatically.
 - [ ] You have run the [Core IT][core-its] successfully.

        if (path == null || path.isEmpty()) {
            // TODO This replacing shouldn't be necessary as user.home should be in the
            // context of the container and thus the value would be interpolated by Plexus
            String basedir = System.getProperty(basedirSysProp);
            if (basedir == null) {
                basedir = System.getProperty("user.dir");
            }

    protected String getProjectsDirectory() {
        return "src/test/projects/plugin-manager";
    }

    @Test
    void testPluginLoading() throws Exception {
        MavenSession session = createMavenSession(null);
        Plugin plugin = new Plugin();
        plugin.setGroupId("org.apache.maven.its.plugins");
        plugin.setArtifactId("maven-it-plugin");
        plugin.setVersion("0.1");

    <exportedPackage>org.codehaus.plexus.util.xml.Xpp3DomBuilder</exportedPackage>
    <exportedPackage>org.codehaus.plexus.util.xml.pull.XmlPullParser</exportedPackage>
    <exportedPackage>org.codehaus.plexus.util.xml.pull.XmlPullParserException</exportedPackage>
    <exportedPackage>org.codehaus.plexus.util.xml.pull.XmlSerializer</exportedPackage>

    <!-- plexus-container, plexus-component-annotations -->

        assertEquals(-1, problem.getColumnNumber());

        problem = new DefaultProblem(null, null, null, -1, 42, null);
        assertEquals(42, problem.getColumnNumber());

        problem = new DefaultProblem(null, null, null, -1, Integer.MAX_VALUE, null);
        assertEquals(Integer.MAX_VALUE, problem.getColumnNumber());

        // this case is not specified, might also return -1

        if (artifact == null) {
            return null;
        }

        String version = artifact.getVersion();
        if (version == null && artifact.getVersionRange() != null) {
            version = artifact.getVersionRange().toString();
        }

        Map<String, String> props = null;

        return treeRoot == null ? null : new MetadataGraph(treeRoot);
    }
    // ----------------------------------------------------------------------------
    public MetadataGraph getGraph(ArtifactScopeEnum scope)
            throws MetadataResolutionException, GraphConflictResolutionException {
        if (treeRoot == null) {
            return null;
        }

        if (conflictResolver == null) {

        // and we want artifact resolution to only return the system scoped artifact itself.
        //
        if (artifact.getScope() != null && artifact.getScope().equals(Artifact.SCOPE_SYSTEM)) {
            return new ResolutionGroup(null, null, null);
        }

        ResolutionGroup cached = cache.get(
                artifact,
                request.isResolveManagedVersions(),

        this.groupId = (groupId != null && !groupId.isEmpty()) ? groupId : null;
        this.artifactId = (artifactId != null && !artifactId.isEmpty()) ? artifactId : null;
        this.classifier = (classifier != null && !classifier.isEmpty()) ? classifier : null;
        this.extension = (extension != null && !extension.isEmpty()) ? extension : null;

     *
     * @param groupId The group id, may be {@code null}.
     * @param artifactId The artifact id, may be {@code null}.
     * @param version The version, may be {@code null}.
     * @return The user-friendly artifact id, never {@code null}.
     */
    static String toId(String groupId, String artifactId, String version) {
        return ((groupId != null && !groupId.isEmpty()) ? groupId : "[unknown-group-id]")
                + ':'