* <p>
 * This builder uses a number of threads equal to the minimum of the degree of concurrency (which is the thread count
 * set with <code>-T</code> on the command-line) and the number of projects to build. As such, building a single project
 * will always result in a sequential build, regardless of the thread count.
 * </p>

        assertTrue(parentFileWasFoundOnChild);

        // read projects together
        List<ProjectBuildingResult> results = projectBuilder.build(toRead, false, configuration);
        assertResultShowNoError(results);
        assertEquals(parentPom, findChildProject(results).getParentFile());
        Collections.reverse(toRead);
        results = projectBuilder.build(toRead, false, configuration);
        assertResultShowNoError(results);

            }

            seen = true;

            tg = aTgList;
            Thread[] ts = new Thread[tg.activeCount()];
            tg.enumerate(ts);

            for (Thread active : ts) {
                String name = active.getName();
                boolean daemon = active.isDaemon();
                assertTrue(daemon, name + " is no daemon Thread.");
            }
        }

            } else {
                projects = session.getProjects();
            }
            for (MavenProject project : projects) {
                ClassLoader tccl = Thread.currentThread().getContextClassLoader();
                MavenProject currentProject = session.getCurrentProject();
                try {

            }

            if (logger.isDebugEnabled()) {
                lifecycleDebugLogger.debugReactorPlan(projectBuilds);
            }

            ClassLoader oldContextClassLoader = Thread.currentThread().getContextClassLoader();
            ReactorBuildStatus reactorBuildStatus = new ReactorBuildStatus(session.getProjectDependencyGraph());

import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * This annotation indicates that the annotated type is <strong>not</strong> threadsafe
 * and should only be used by a single thread.
 *
 * @see ThreadSafe
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.TYPE)

    /**
     * Sets the currently active session. Some legacy components are basically stateful and their API is missing
     * parameters that would be required to delegate to a stateless component. Saving the session (in a thread-local
     * variable) is our best effort to record any state that is required to enable proper delegation.
     *
     * @param session The currently active session, may be {@code null}.
     */

            return new Metadata(new MetadataStaxReader().read(in, false));
        } catch (FileNotFoundException e) {
            throw new RepositoryMetadataReadException("Cannot read metadata from '" + mappingFile + "'", e);
        } catch (IOException | XMLStreamException e) {
            throw new RepositoryMetadataReadException(
                    "Cannot read metadata from '" + mappingFile + "': " + e.getMessage(), e);
        }

                    exceptions.add(e);
                }
            }
            try {
                return doRead(request);
            } catch (IOException e) {
                exceptions.forEach(e::addSuppressed);
                throw e;
            }
        } else {
            return doRead(request);
        }
    }

    private Path doLocateExistingPom(Path project) {
        if (project == null) {

    }

    protected static File getFileForClasspathResource(String resource)
            throws FileNotFoundException, URISyntaxException {
        ClassLoader cloader = Thread.currentThread().getContextClassLoader();

        URL resourceUrl = cloader.getResource(resource);

        if (resourceUrl == null) {
            throw new FileNotFoundException("Unable to find: " + resource);
        }