final private function add_setting( $classname, $setting, $default, $type, $capability, $transport, $sanitize_callback ) {

		$this->wp_customize->add_setting(
			new $classname(
				$this->wp_customize,
				$setting,
				[
					'default'           => $default,
					'type'              => $type,
					'capability'        => $capability,
					'transport'         => $transport,
					'sanitize_callback' => $sanitize_callback,
				]
			)
		);

	}