MDL-76583 core_external: external_single_structure coding style fixes

lib/external/classes/external_single_structure.php

@@ -22,11 +22,10 @@ namespace core_external;
  * @package    core_external
  * @copyright  2009 Petr Skodak
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
- * @since Moodle 2.0
  */
 class external_single_structure extends external_description {
 
-     /** @var array Description of array keys key=>external_description */
+    /** @var array Description of array keys key=>external_description */
     public $keys;
 
     /**
@@ -34,12 +33,15 @@ class external_single_structure extends external_description {
      *
      * @param array $keys
      * @param string $desc
-     * @param bool $required
+     * @param int $required
      * @param array $default
-     * @since Moodle 2.0
      */
-    public function __construct(array $keys, $desc='',
-            $required=VALUE_REQUIRED, $default=null) {
+    public function __construct(
+        array $keys,
+        $desc = '',
+        $required = VALUE_REQUIRED,
+        $default = null
+    ) {
         parent::__construct($desc, $required, $default);
         $this->keys = $keys;
     }