Youtube Data API, update tags order?

I'm trying to update tags of a video with Youtube Data API using google-api-php-clientand the tag order is being ignored. I've set them in array in the desired order but they always change to alphabetical order. How do i solve this? For example the following array:

$keywords = array();$keywords[0] = "one";$keywords[1] = "two";$keywords[2] = "three";$snippet->setTags($keywords);

In Youtube, the tags display as one, three, two which is in alphabetical order. How can I solve this? The correct order is `one, two, three.