docs: add comments

Author: kenjis

system/Cache/Handlers/FileHandler.php

@@ -44,6 +44,8 @@ class FileHandler extends BaseHandler
     protected $mode;
 
     /**
+     * Note: Use `CacheFactory::getHandler()` to instantiate.
+     *
      * @throws CacheException
      */
     public function __construct(Cache $config)

system/Cache/Handlers/MemcachedHandler.php

@@ -42,6 +42,9 @@ class MemcachedHandler extends BaseHandler
         'raw'    => false,
     ];
 
+    /**
+     * Note: Use `CacheFactory::getHandler()` to instantiate.
+     */
     public function __construct(Cache $config)
     {
         $this->prefix = $config->prefix;

system/Cache/Handlers/PredisHandler.php

@@ -43,6 +43,9 @@ class PredisHandler extends BaseHandler
      */
     protected $redis;
 
+    /**
+     * Note: Use `CacheFactory::getHandler()` to instantiate.
+     */
     public function __construct(Cache $config)
     {
         $this->prefix = $config->prefix;

system/Cache/Handlers/RedisHandler.php

@@ -42,6 +42,9 @@ class RedisHandler extends BaseHandler
      */
     protected $redis;
 
+    /**
+     * Note: Use `CacheFactory::getHandler()` to instantiate.
+     */
     public function __construct(Cache $config)
     {
         $this->prefix = $config->prefix;

system/Cache/Handlers/WincacheHandler.php

@@ -22,6 +22,9 @@
  */
 class WincacheHandler extends BaseHandler
 {
+    /**
+     * Note: Use `CacheFactory::getHandler()` to instantiate.
+     */
     public function __construct(Cache $config)
     {
         $this->prefix = $config->prefix;