/**
     * Gets the project settings source.
     *
     * @return the project settings source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getProjectSettingsSource();

    /**
     * Gets the user settings source.
     *
     * @return the user settings source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserSettingsSource();

        Source globalSource = request.getGlobalSettingsSource().orElse(null);
        Settings global = readSettings(globalSource, false, request, problems);

        Source projectSource = request.getProjectSettingsSource().orElse(null);
        Settings project = readSettings(projectSource, true, request, problems);

        Source userSource = request.getUserSettingsSource().orElse(null);