assertInstanceOf(Sources.ResolvedPathSource.class, source);
        assertNull(source.getPath());
        assertEquals(path.toString(), source.getLocation());
        assertEquals(modelId, source.getModelId());
    }

    @Test
    void testPathSourceFunctionality() {
        // Test basic source functionality
        Path path = Paths.get("/tmp");

    /**
     * Get the identifier of the POM in the format {@code
     * <groupId>:<artifactId>:<version>}.
     *
     * @return String
     */
    public String getModelId() {
        return this.modelId;
    } // -- String getModelId()

    /**
     * Set the path/URL of the POM or {@code null} if unknown.
     *
     * @param location
     */
    public void setLocation(String location) {

    @Test
    void testBuildSourceHasNoModelId() {
        Path path = Paths.get("/tmp/pom.xml");
        ModelSource source = Sources.buildSource(path);

        assertNotNull(source);
        assertNull(source.getModelId(), "Build sources should not have a modelId");
        assertEquals(path, source.getPath());
    }

    @Test
    void testResolvedSourceWithModelId() {
        String location = "/tmp/resolved-pom.xml";

     *
     * @return the model identifier, or {@code null} if not available or not applicable
     * @since 4.0.0
     */
    @Nullable
    default String getModelId() {
        return null;
    }

    /**
     * Interface for locating POM files within a project structure.
     * Implementations of this interface provide the ability to find POM files

                        if (result == null || result.getEffectiveModel() == null) {
                            throw new ProjectBuildingException(
                                    e.getModelId(), e.getMessage(), pomFile != null ? pomFile.toFile() : null, e);
                        }
                        // validation error, continue project building and delay failing to help IDEs
                        error = e;

            this.modelId = modelId;
        }

        @Override
        public Path getPath() {
            return null;
        }

        @Override
        @Nullable
        public String getModelId() {
            return modelId;
        }

        @Override
        public Source resolve(String relative) {
            return null;
        }

        @Override
        @Nullable

                            && p.getLocation("version").getSource() != null
                            && defaulModelId.equals(
                                    p.getLocation("version").getSource().getModelId()))
                    .distinct()
                    .map(Plugin::getArtifactId) // managed by us, groupId is always o.a.m.plugins
                    .toList();
            if (!unversionedPlugins.isEmpty()) {

      </fields>
      <codeSegments>
        <codeSegment>
          <version>4.0.0+</version>
          <code>
            <![CDATA[
    @Override
    public String toString() {
        return getModelId() + " " + getLocation();
    }
            ]]>
          </code>
        </codeSegment>
      </codeSegments>
    </class>
  </classes>