Error in update snippet (tags) [PHP]

[StevenFlecha]

In the PHP video snippet update example that adds tags it states:

      $video = $listResponse[0];
      $videoSnippet = $video['snippet'];
      $tags = $videoSnippet['tags'];
      // Preserve any tags already associated with the video. If the video does
      // not have any tags, create a new list. Replace the values "tag1" and
      // "tag2" with the new tags you want to associate with the video.
      if (is_null($tags)) {
        $tags = array("tag1", "tag2");
      } else {
        array_push($tags, "tag1", "tag2");
      }
      // Set the tags array for the video snippet
      $videoSnippet['tags'] = $tags;
      // Update the video resource by calling the videos.update() method.
      $updateResponse = $youtube->videos->update("snippet", $video);

I can't see how that is ever gonna work, seems like its written by a JS programmer :)
$video isn't changed proposed change:

$video = $listResponse[0];
$tags = $video[''snippet']['tags'];
if (is_null($tags)) {
      $tags = array("tag1", "tag2");
} else {
     array_push($tags, "tag1", "tag2");
}
$video[''snippet']['tags'] = $tags;
$updateResponse = $youtube->videos->update("snippet", $video);