import java.util.ArrayList;
import java.util.Collection;

/**
 * This is the main graph data structure used by the RepositorySystem to present tree and graph objects.
 *
 *
 */
@Deprecated
public class MetadataGraph {
    /** all graph nodes */
    Collection<MetadataGraphNode> nodes;

    /** entry point for tree-like structures */
    MetadataGraphNode entry;

    public MetadataGraph(MetadataGraphNode entry) {

          <type>DOM</type> <!-- DOM for Maven 2.0.9/2.3.3 -->
          <description>
            Toolchain identification information, which will be matched against project requirements.
            &lt;p>Actual content structure is completely open: each toolchain type will define its own format and
            semantics.
            &lt;p>This is generally a properties format: {@code &lt;name&gt;value&lt;/name&gt;} with predefined

 <parent>
   <groupId></groupId>
   <artifactId></artifactId>
   <version></version>
 </parent>
</project>
+-----+

Extending the POM in the future

  In order to anticipate changes in the structure of the POM as new releases of
  maven occur, the maven inheritance model must be pinned against a particular
  modelVersion. This is required so that a change from modelVersion 4.0.0 to

      pre-calculated execution plan that stays the same during the execution.

      If deciding to add mutable state to this class, it should be at least considered to
      separate this into a separate mutable structure.

    */

    private final List<ExecutionPlanItem> planItem;

    private final Map<String, ExecutionPlanItem> lastMojoExecutionForAllPhases;

    final List<String> phasesInExecutionPlan;

identify which stub creates that specific piece of data.

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.

  if [ ! -x "$JAVACMD" ] ; then
    echo "The java(1) command does not exist in PATH nor is JAVA_HOME set, so Apache Maven cannot be started." >&2
    exit 1
  fi
fi

# traverses directory structure from process work directory to filesystem root
# first directory with .mvn subdirectory is considered project base directory
find_maven_basedir() {
(
  basedir=`find_file_argument_basedir "$@"`
  wdir="$basedir"

       <name>theme</name>
       <value>classic</value>
     </parameter>
   </parameters>
  </plugin>
</plugins>
+-----+

Unified source directory

 Unified source directory structure that is analogous to the repository
 itself. This way locations of intermediary artifacts of a build would be
 in a known location. This would also help with developer setup i.e. getting

        assertEquals(depender1, sortedProjects.get(1));
    }

    @Test
    void testVerifyExpectedParentStructure() throws CycleDetectedException, DuplicateProjectException {
        // This test verifies the baseline structure used in subsequent tests. If this fails, the rest will fail.
        ProjectDependencyGraph graph = threeProjectsDependingOnASingle();
        final List<MavenProject> sortedProjects = graph.getSortedProjects();

 resources required to run Maven. Each subsequent plugin realm contains the
 JAR plugin as well as its dependencies. The realms noted above are setup
 in a hierarchical structure where the resources in the parent realms are
 available but the <<realm is searched first before a search is made in
 the parent realm>>.

 Plugins are guaranteed to be provided the resources found in

MojoDescriptor for the goal that needs to be run. In the MojoDescriptor we are interested in the <configuration/> element and <parameters/> element. From these elements we need to make a component configuration for the MojoExecution. The actual DOM like structure we create is of type PlexusConfiguration and is the type we use with the ComponentConfigurator to initialize fields in a Plexus component. Typically this is done within Plexus with the configuration supplied with component configuration, but in Maven...