getRequestLink example

  protected function buildWrappedResponse(TopLevelDataInterface $data, Request $request, IncludedData $includes, $response_code = 200, array $headers = [], LinkCollection $links = NULL, array $meta = []) {
    $links = ($links ?: new LinkCollection([]));
    if (!$links->hasLinkWithKey('self')) {
      $self_link = new Link(new CacheableMetadata(), self::getRequestLink($request), 'self');
      $links = $links->withLink('self', $self_link);
    }
    $document = new JsonApiDocumentTopLevel($data, $includes, $links, $meta);
    if (!$request->isMethodCacheable()) {
      return new ResourceResponse($document, $response_code, $headers);
    }
    $response = new CacheableResourceResponse($document, $response_code, $headers);
    $cacheability = (new CacheableMetadata())->addCacheContexts([
      // Make sure that different sparse fieldsets are cached differently.       'url.query_args:fields',
      // Make sure that different sets of includes are cached differently.