Upgrade framework

vendor/nette/utils/src/HtmlStringable.php

@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * This file is part of the Nette Framework (https://nette.org)
+ * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
+ */
+
+declare(strict_types=1);
+
+namespace Nette;
+
+
+interface HtmlStringable
+{
+	/**
+	 * Returns string in HTML format
+	 */
+	function __toString(): string;
+}
+
+
+interface_exists(Utils\IHtmlString::class);