đã tạo được test case của createUser

vendor/php-webdriver/webdriver/lib/Firefox/FirefoxPreferences.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Facebook\WebDriver\Firefox;
+
+/**
+ * Constants of common Firefox profile preferences (about:config values).
+ * @see http://kb.mozillazine.org/Firefox_:_FAQs_:_About:config_Entries
+ *
+ * @codeCoverageIgnore
+ */
+class FirefoxPreferences
+{
+    /** @var string Port WebDriver uses to communicate with Firefox instance */
+    public const WEBDRIVER_FIREFOX_PORT = 'webdriver_firefox_port';
+    /** @var string Should the reader view (FF 38+) be enabled? */
+    public const READER_PARSE_ON_LOAD_ENABLED = 'reader.parse-on-load.enabled';
+    /** @var string Browser homepage */
+    public const BROWSER_STARTUP_HOMEPAGE = 'browser.startup.homepage';
+    /** @var string Should the Devtools JSON view be enabled? */
+    public const DEVTOOLS_JSONVIEW = 'devtools.jsonview.enabled';
+
+    private function __construct()
+    {
+    }
+}