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
---------------

/**
 * A test which demonstrates maven's recursive inheritance where
 * a distinct value is taken from each parent contributing to
 * the final model of the project being assembled. There is no
 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values

    }

    /**
     * The event "artifact resolved" if fired WHENEVER an artifact is resolved, BUT it happens also when an artifact
     * descriptor (model, the POM) is being built, and parent (and parent of parent...) is being asked for. Hence, this
     * method "filters" out in WHICH artifact are we interested in, but it intentionally neglects extension as

            // that would happen here should cause the build to fail at a later stage
            // (when actually parsing the POM) and will lead to a better exception being
            // displayed to the user, so just bail out and return false.
        }
        return false;
    }

     * cache.
     *
     * @param project The project that employs the plugin realm, must not be {@code null}.
     * @param record The cache record being used for the project, must not be {@code null}.
     */
    void register(MavenProject project, Key key, CacheRecord record);

                    String str = ownerMojo != null ? " The " + ownerMojo.getId() : "An";
                    String msg = str + " aggregator mojo is already being executed "
                            + "in this parallel build, those kind of mojos require exclusive access to "
                            + "reactor to prevent race conditions. This mojo execution will be blocked "

            Other values define only the prefix of classes/resources being exposed. Their binary name must be equal to the prefix or starting with the prefix (followed by "." or "$").

import org.apache.maven.lifecycle.internal.ExecutionPlanItem;
import org.apache.maven.model.Plugin;
import org.apache.maven.plugin.MojoExecution;
import org.apache.maven.plugin.descriptor.MojoDescriptor;

// TODO lifecycles being executed
// TODO what runs in each phase
// TODO plugins that need downloading
// TODO project dependencies that need downloading

            }
        } else {
            String type = artifact.getProperty("type", "");
            File outputDirectory = new File(project.getBuild().getOutputDirectory());

            // Check if the project is being built during this session, and if we can expect any output.
            // There is no need to check if the build has created any outputs, see MNG-2222.
            boolean projectCompiledDuringThisSession =

 * interpolation can be added. This allows to have an entity which is useful in a runtime while preserving the model so
 * that it can be marshalled and unmarshalled without being tainted by runtime requirements.
 * </p>
 * <p>
 * With changes during 3.2.2 release MavenProject is closer to being immutable after construction with the removal of
 * all components from this class, and the upfront construction taken care of entirely by the {@link ProjectBuilder}.