Weak hands cannot be planted, meager skills have no foundation. Shallow wisdom is futile, how can one hope for a good name?扰扰从役倦，屑屑身事微。少壮轻年月，迟暮惜光辉。
upgrades();
if ( empty( $upgrades ) ) {
return;
}
// Run any available upgrades.
foreach ( $upgrades as $upgrade ) {
if ( is_callable( $upgrade ) ) {
$upgrade();
}
}
// Update version post upgrade(s).
update_option( 'wp_mail_smtp_version', WPMS_PLUGIN_VER );
}
/**
* Whether we need to perform an upgrade.
*
* @since 1.1.0
*
* @return array
*/
protected function upgrades() {
$version = get_option( 'wp_mail_smtp_version' );
/**
* Filters the list of upgrade callbacks to run.
*
* @since 4.4.0
*
* @param array $upgrades List of upgrade callbacks to run.
* @param strin