Fix CS/WS issues

Author: sebastianbergmann

src/TextUI/XmlConfiguration/Migration/SnapshotNodeList.php

@@ -15,14 +15,19 @@
 use DOMNodeList;
 use IteratorAggregate;
 
-class SnapshotNodeList implements Countable, IteratorAggregate
+/**
+ * @internal This class is not covered by the backward compatibility promise for PHPUnit
+ */
+final class SnapshotNodeList implements Countable, IteratorAggregate
 {
-    /** @var DOMNode[] */
+    /**
+     * @var DOMNode[]
+     */
     private $nodes = [];
 
-    public static function fromNodeList(DOMNodeList  $list): self
+    public static function fromNodeList(DOMNodeList $list): self
     {
-        $snapshot = new self();
+        $snapshot = new self;
 
         foreach ($list as $node) {
             $snapshot->nodes[] = $node;
@@ -36,7 +41,7 @@ public function count(): int
         return count($this->nodes);
     }
 
-    public function getIterator()
+    public function getIterator(): ArrayIterator
     {
         return new ArrayIterator($this->nodes);
     }