PHP Deprecation: Fix creation of dynamic property. (#413)

src/Comment_Command.php

@@ -41,6 +41,8 @@ class Comment_Command extends CommandWithDBObject {
 		'comment_author_email',
 	];
 
+	private $fetcher;
+
 	public function __construct() {
 		$this->fetcher = new CommentFetcher();
 	}

src/Post_Command.php

@@ -36,6 +36,8 @@ class Post_Command extends CommandWithDBObject {
 		'post_status',
 	];
 
+	private $fetcher;
+
 	public function __construct() {
 		$this->fetcher = new PostFetcher();
 	}

src/Post_Term_Command.php

@@ -33,6 +33,8 @@
 class Post_Term_Command extends CommandWithTerms {
 	protected $obj_type = 'post';
 
+	private $fetcher;
+
 	public function __construct() {
 		$this->fetcher = new PostFetcher();
 	}

src/Site_Command.php

@@ -33,6 +33,8 @@ class Site_Command extends CommandWithDBObject {
 	protected $obj_type   = 'site';
 	protected $obj_id_key = 'blog_id';
 
+	private $fetcher;
+
 	public function __construct() {
 		$this->fetcher = new SiteFetcher();
 	}

src/User_Command.php

@@ -48,6 +48,7 @@ class User_Command extends CommandWithDBObject {
 	private $cap_fields = [
 		'name',
 	];
+	private $fetcher;
 
 	public function __construct() {
 		$this->fetcher = new UserFetcher();

src/User_Meta_Command.php

@@ -33,6 +33,8 @@
 class User_Meta_Command extends CommandWithMeta {
 	protected $meta_type = 'user';
 
+	private $fetcher;
+
 	public function __construct() {
 		$this->fetcher = new UserFetcher();
 	}