Add a few more ??=

Author: tigitz

Caster/MemcachedCaster.php

@@ -37,8 +37,8 @@ public static function castMemcached(\Memcached $c, array $a, Stub $stub, bool $
 
     private static function getNonDefaultOptions(\Memcached $c): array
     {
-        self::$defaultOptions = self::$defaultOptions ?? self::discoverDefaultOptions();
-        self::$optionConstants = self::$optionConstants ?? self::getOptionConstants();
+        self::$defaultOptions ??= self::discoverDefaultOptions();
+        self::$optionConstants ??= self::getOptionConstants();
 
         $nonDefaultOptions = [];
         foreach (self::$optionConstants as $constantKey => $value) {
@@ -56,7 +56,7 @@ private static function discoverDefaultOptions(): array
         $defaultMemcached->addServer('127.0.0.1', 11211);
 
         $defaultOptions = [];
-        self::$optionConstants = self::$optionConstants ?? self::getOptionConstants();
+        self::$optionConstants ??= self::getOptionConstants();
 
         foreach (self::$optionConstants as $constantKey => $value) {
             $defaultOptions[$constantKey] = $defaultMemcached->getOption($value);