void setDegreeOfConcurrency(int degreeOfConcurrency);

    /**
     * @return the degree of concurrency for the build.
     */
    int getDegreeOfConcurrency();

    // Recursive (really to just process the top-level POM)
    MavenExecutionRequest setRecursive(boolean recursive);

    boolean isRecursive();

    MavenExecutionRequest setPom(File pom);

    File getPom();

    // Errors

 of models you may specify:

 all of the models that you specify are collected to produce a lineage and then the super model is place at
 the top of that lineage to provide default values.

 The super model is where we place all the values which we believe to be standard, values that can be shared and
 utilized across all your Maven projects.

+-----+
 m0 <- m1 <- m2

code is a great way to give something back to the open source community. Before
you dig right into the code, there are a few guidelines that we need
contributors to follow so that we can have a chance of keeping on top of
things.

Some of the ideas are documented in the [Maven Wiki][maven-wiki]
which might be interesting to read and for further discussion.

Getting Started
---------------

     * filter is applied (like in Maven 3).
     * <p>
     * Supported filters:
     * <ul>
     *     <li>"h" or "h(num)" - highest version or top list of highest ones filter</li>
     *     <li>"l" or "l(num)" - lowest version or bottom list of lowest ones filter</li>
     *     <li>"s" - contextual snapshot filter</li>

     * directory pointed at by the {@code -f/--file} command line argument.
     */
    @Nonnull
    Path getTopDirectory();

    /**
     * Gets the root directory of the session, which is the root directory for the top directory project.
     *
     * @throws IllegalStateException if the root directory could not be found
     * @see #getTopDirectory()
     * @see Project#getRootDirectory()
     */
    @Nonnull

     * Returns a boolean indicating if the project is the top level project for
     * this reactor build.  The top level project may be different from the
     * {@code rootDirectory}, especially if a subtree of the project is being
     * built, either because Maven has been launched in a subdirectory or using
     * a {@code -f} option.
     *
     * @return {@code true} if the project is the top level project for this build
     */

        File f = getFileForClasspathResource("canonical-pom.xml");

        MavenProject project = getProject(f);

        // ----------------------------------------------------------------------
        // Top-level elements
        // ----------------------------------------------------------------------

        assertEquals("4.0.0", project.getModelVersion());

The most important stubs are:
LifecycleExecutionPlanCalculatorStub
ProjectDependencyGraphStub

Since they define the primary structure of the project/build.

The stubs define three top-level targets that are defined in  LifecycleTaskSegmentCalculatorStub;
clean, aggr and install. "aggr" is an aggregating task while clean and install are lifecyclephases.
There will be three items in the task list for this dataset.

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

# Apache Lucene and Solr have separate repositories now!

Solr has become a top-level Apache project and main line 
development for Lucene and Solr is happening in each 
project's git repository now:

- Lucene: <https://gitbox.apache.org/repos/asf/lucene.git>

        createLocalArtifact("h", "1.0");
        artifactResolver.resolveTransitively(
                Collections.singleton(g), projectArtifact, remoteRepositories(), localRepository(), null);

        // we want to see all top-level thread groups
        ThreadGroup tg = Thread.currentThread().getThreadGroup();
        while (tg.getParent() == null) {
            tg = tg.getParent();
        }