String projectId = extractProjectId(r);
                    File sourcePomFile = r.getSource() != null && r.getSource().getPath() != null
                            ? r.getSource().getPath().toFile()
                            : null;
                    results.add(new DefaultProjectBuildingResult(

        assertNotNull(resolved);
        assertNotNull(resolved.getPath());
        Optional<Path> op = session.getArtifactPath(resolved);
        assertTrue(op.isPresent(), "Expected " + op + ".isPresent() to return true");
        assertEquals(resolved.getPath(), op.get());
    }

    @Test
    void testBuildProject() {

     *
     * @return an optional containing the path to the project, or empty if not specified
     */
    @Nonnull
    Optional<Path> getPath();

    /**
     * Gets the source of the project to build.
     * This is an alternative to specifying a path, allowing the project to be built from
     * a model source such as a string or input stream.
     *

    }

    @Nonnull
    @Override
    public Optional<Path> getPath(@Nonnull Project project) {
        requireNonNull(project, "project" + " cannot be null");
        Optional<ProducedArtifact> mainArtifact = project.getMainArtifact();
        return mainArtifact.flatMap(artifactManager::getPath);
    }

    @Nonnull
    @Override

 */
@Experimental
@Immutable
public interface DownloadedArtifact extends Artifact {

    /**
     * {@return the a path to the file that has been downloaded to the file system}.
     */
    Path getPath();

    }

    @Override
    public ModelSource2 getRelatedSource(String relPath) {
        relPath = relPath.replace('\\', File.separatorChar).replace('/', File.separatorChar);

        Path relatedPom = getPath().getParent().resolve(relPath);

        if (Files.isDirectory(relatedPom)) {
            // TODO figure out how to reuse ModelLocator.locatePom(File) here
            relatedPom = relatedPom.resolve("pom.xml");
        }

        URI uri = URI.create("jar:" + gradleRuntimeApiInfoJar.getAbsoluteFile().toURI());
        try (FileSystem fs = FileSystems.newFileSystem(uri, Collections.emptyMap())) {
            Path upgradedPropertiesJson = fs.getPath(UPGRADED_PROPERTIES_FILE);
            if (Files.exists(upgradedPropertiesJson)) {
                Files.copy(upgradedPropertiesJson, to.getAsFile().get().toPath(), StandardCopyOption.REPLACE_EXISTING);
            } else {

    Path createFile() throws IOException {
      Path file = java.nio.file.Files.createTempFile("SinkSourceFile", "txt");
      fileThreadLocal.set(file);
      return file;
    }

    Path getPath() {
      return fileThreadLocal.get();
    }

    // acts as an override in subclasses that implement SourceSinkFactory
    @SuppressWarnings("EffectivelyPrivate")

            } else {
                Path file = artifact.getPath();
                log.debug("  Included {} located at {}", id, file);
                realm.addURL(file.toUri().toURL());
            }
        }
        return CoreExtensionEntry.discoverFrom(
                realm,
                Collections.singleton(artifacts.get(0).getPath().toFile()),

                String msg = "dependency collection step for " + stepData.getContext();
                if (detailed) {
                    msg += ". Path to offending node from root:\n";
                    msg += stepData.getPath().stream()
                            .map(n -> " -> " + n.toString())
                            .collect(Collectors.joining("\n"));
                    msg += "\n => " + stepData.getNode();
                }