register_section_type example

    public function wp_loaded() {

        /* * Unconditionally register core types for panels, sections, and controls * in case plugin unhooks all customize_register actions. */
        $this->register_panel_type( 'WP_Customize_Panel' );
        $this->register_panel_type( 'WP_Customize_Themes_Panel' );
        $this->register_section_type( 'WP_Customize_Section' );
        $this->register_section_type( 'WP_Customize_Sidebar_Section' );
        $this->register_section_type( 'WP_Customize_Themes_Section' );
        $this->register_control_type( 'WP_Customize_Color_Control' );
        $this->register_control_type( 'WP_Customize_Media_Control' );
        $this->register_control_type( 'WP_Customize_Upload_Control' );
        $this->register_control_type( 'WP_Customize_Image_Control' );
        $this->register_control_type( 'WP_Customize_Background_Image_Control' );
        $this->register_control_type( 'WP_Customize_Background_Position_Control' );
        $this->register_control_type( 'WP_Customize_Cropped_Image_Control' );
        $this->register_control_type( 'WP_Customize_Site_Icon_Control' );
        $this->register_control_type( 'WP_Customize_Theme_Control' );