protected function apply_sanitize_callback( $output, $value ) {
		if ( isset( $output['sanitize_callback'] ) && null !== $output['sanitize_callback'] ) {

			// If the sanitize_callback is invalid, return the value.
			if ( ! is_callable( $output['sanitize_callback'] ) ) {
				return $value;
			}
			return call_user_func( $output['sanitize_callback'], $this->value );
		}
		return $value;
	}