Issue #3487659 by alan delval, abhishek_gupta1, liam morland: TypeError:...

Issue #3487659 by alan delval, abhishek_gupta1, liam morland: TypeError: ..\MetadataBubblingUrlGenerator::generateFromRoute(): Argument #2 ($parameters) must be of type array

src/Toc.php

@@ -340,7 +340,7 @@ class Toc implements TocInterface {
           '#markup' => $header_html,
           '#allowed_tags' => $this->getAllowedTags(),
         ],
-        'url' => Url::fromRoute('<none>', NULL, [
+        'url' => Url::fromRoute('<none>', [], [
             'fragment' => $header_id,
           ]
         ),