warn(CharSequence); public void warn(CharSequence, Throwable); public void warn(Throwable); public void error(CharSequence); public void error(CharSequence, Throwable); public void error(Throwable); private void print(String, CharSequence); private void print(String, Throwable); private void print(String, CharSequence, Throwable); public boolean isDebugEnabled(); public boolean isInfoEnabled(); public boolean isWarnEnabled(); public boolean isErrorEnabled(); } org/apache/maven/plugin/Mojo$1.class package...

** Control over downloads

  Find the control point for m2 using maven-wagon. At this point, inject
  a offline status parameter which is used when retrieving the specific Wagon.

  If <<<offline == true>>>:

  * If the wagon is not bound to "file://", then ignore the request and print
    a debug message.

  * If the wagon is bound to "file://" then:

     * <p>
     * Shortcut for {@code getService(ArtifactFactory.class).create(...)}.
     *
     * @param coordString the string having "standard" coordinate.
     * @return coordinate used to point to the artifact
     *
     * @see org.apache.maven.api.services.ArtifactCoordinateFactory#create(Session, String)
     */
    @Nonnull
    ArtifactCoordinate createArtifactCoordinate(@Nonnull String coordString);

                extensionRecord = setupExtensionsRealm(project, plugin, repositorySession);
            } catch (PluginManagerException e) {
                // extensions realm is expected to be fully setup at this point
                // any exception means a problem in maven code, not a user error
                throw new IllegalStateException(e);
            }

            ClassRealm pluginRealm = extensionRecord.getRealm();

                MavenProject parent = parentPomFile != null ? projects.get(parentPomFile.toFile()) : null;
                if (parent == null) {
                    //
                    // At this point the DefaultModelBuildingListener has fired and it populates the
                    // remote repositories with those found in the pom.xml, along with the existing externally
                    // defined repositories.

     * be able to accept <code>relative</code> parameter values that
     * <ul>
     * <li>use either / or \ file path separator,</li>
     * <li>have .. parent directory references,</li>
     * <li>point either at file or directory.</li>
     * </ul>
     *
     * @param relative is the path of the requested source relative to this source
     * @return related source or <code>null</code> if no such source
     */

        }
        return artifactGeneratorFactories;
    }

    protected Map<String, ArtifactGeneratorFactory> createArtifactGeneratorFactories() {
        // by default none, this is extension point
        return new HashMap<>();
    }

    private Map<String, ArtifactDecoratorFactory> artifactDecoratorFactories;

    public final Map<String, ArtifactDecoratorFactory> getArtifactDecoratorFactories() {

                PACKAGE.getPhase(),
                "BEER",
                INSTALL.getPhase());

        // The two phases below are really for future expansion, some would say they lack a drink
        // The point being that they do not really have to match the "real" stuff,
        List<String> stubCleanCycle = Arrays.asList(PRE_CLEAN.getPhase(), CLEAN.getPhase(), POST_CLEAN.getPhase());

        List<String> stubSiteCycle =

             */
            if (aggregating && areAllDependenciesInReactor(session.getProjects(), result.getUnresolvedDependencies())) {
                logger.warn("The following dependencies could not be resolved at this point of the build"
                        + " but seem to be part of the reactor:");

                for (Dependency dependency : result.getUnresolvedDependencies()) {
                    logger.warn("o {}", dependency);

        for (RepositorySystemSessionExtender extender : sessionExtenders.values()) {
            extender.extend(request, configProps, mirrorSelector, proxySelector, authSelector);
        }

        // at this point we have "config" with pure MANDATORY resolver config, so resolver final config properties are
        // mergedProperties + configProperties
        HashMap<String, Object> finalConfigProperties = new HashMap<>();