PluginPrefixResult result = resolveFromProject(request);

        if (result == null) {
            result = resolveFromRepository(request);

            if (result == null) {
                throw new NoPluginFoundForPrefixException(
                        request.getPrefix(),
                        request.getPluginGroups(),

            setPom(project.getModel());
        }

        setPluginGroups(session.getPluginGroups());
    }

    public String getPrefix() {
        return prefix;
    }

    public DefaultPluginPrefixRequest setPrefix(String prefix) {
        this.prefix = prefix;

        return this;
    }

    public List<String> getPluginGroups() {
        return pluginGroups;
    }

        }

        return this;
    }

    @Override
    public MavenExecutionRequest addPluginGroup(String pluginGroup) {
        if (!getPluginGroups().contains(pluginGroup)) {
            getPluginGroups().add(pluginGroup);
        }

        return this;
    }

    @Override
    public MavenExecutionRequest addPluginGroups(List<String> pluginGroups) {

    /**
     * Gets the list of group ids to scan for the plugin prefix.
     *
     * @return The list of group ids to scan for the plugin prefix, never {@code null}.
     */
    List<String> getPluginGroups();

    /**
     * Sets the list of group ids to scan for the plugin prefix.
     *
     * @param pluginGroups The list of group ids to scan for the plugin prefix, may be {@code null}.

    public ProjectBuildingRequest getProjectBuildingRequest() {
        return request.getProjectBuildingRequest().setRepositorySession(getRepositorySession());
    }

    public List<String> getPluginGroups() {
        return request.getPluginGroups();
    }

    public boolean isOffline() {
        return request.isOffline();
    }

    public MavenProject getTopLevelProject() {
        return topLevelProject;
    }

                    "usePluginRegistry",
                    null,
                    "is deprecated and has no effect.");
        }

        List<String> pluginGroups = settings.getPluginGroups();

        if (pluginGroups != null) {
            for (int i = 0; i < pluginGroups.size(); i++) {
                String pluginGroup = pluginGroups.get(i);

                .pluginGroups(Arrays.asList("org.codehaus.plexus"))
                .build();

        Settings merged = SettingsUtilsV4.merge(dominant, recessive);

        List<String> pluginGroups = merged.getPluginGroups();

        assertNotNull(pluginGroups);
        assertEquals(3, pluginGroups.size());
        assertEquals("org.apache.maven.plugins", pluginGroups.get(0));

            return request;
        }

        request.setOffline(settings.isOffline());

        request.setInteractiveMode(settings.isInteractiveMode());

        request.setPluginGroups(settings.getPluginGroups());

        request.setLocalRepositoryPath(settings.getLocalRepository());

        for (Server server : settings.getServers()) {
            server = server.clone();

    // Mirrors
    List<Mirror> getMirrors();

    MavenExecutionRequest setMirrors(List<Mirror> mirrors);

    MavenExecutionRequest addMirror(Mirror mirror);

    // Plugin groups
    List<String> getPluginGroups();

    MavenExecutionRequest setPluginGroups(List<String> pluginGroups);

    MavenExecutionRequest addPluginGroup(String pluginGroup);

    MavenExecutionRequest addPluginGroups(List<String> pluginGroups);