Explicitly declare options property of UniqueNode (#80)

Author: ondrejbouda

src/XmlStringStreamer/Parser/UniqueNode.php

@@ -70,6 +70,11 @@ class UniqueNode implements ParserInterface
      */
     protected $preCapture;
 
+    /**
+     * @var array<string, mixed>
+     */
+    private $options;
+
     /**
      * Parser constructor
      * @param array $options An options array