* @return The populated execution request, never {@code null}.
     * @throws MavenExecutionRequestPopulationException If the execution request could not be populated.
     */
    MavenExecutionRequest populateDefaults(MavenExecutionRequest request)
            throws MavenExecutionRequestPopulationException;

    /*if_not[MAVEN4]*/

    /**

            }

            request.setToolchains(groupedToolchains);
        }
        return request;
    }

    @Override
    public MavenExecutionRequest populateDefaults(MavenExecutionRequest request)
            throws MavenExecutionRequestPopulationException {
        baseDirectory(request);

        localRepository(request);

        populateDefaultPluginGroups(request);

            MavenExecutionRequest mer = new DefaultMavenExecutionRequest();
            invoker.populateRequest(context, new DefaultLookup(container), mer);
            mer = container.lookup(MavenExecutionRequestPopulator.class).populateDefaults(mer);
            return Collections.unmodifiableList(container
                    .lookup(BootstrapCoreExtensionManager.class)
                    .loadCoreExtensions(mer, providedArtifacts, extensions));

            MavenExecutionRequest request = DefaultMavenExecutionRequest.copy(cliRequest.request);

            populateRequest(cliRequest, request);

            request = executionRequestPopulator.populateDefaults(request);

            BootstrapCoreExtensionManager resolver = container.lookup(BootstrapCoreExtensionManager.class);