Custom ISearchable content type - add tags to the search document?

Question

If I have a custom content type that is searchable (and implements ITaggableContentType)...how do I append content tags to the search document within the "GetContentToIndex" method?

Mathew D&#39;Amico · Answer

Here is an example of how tags are added for comments: 
 var tags = TagService.GetTags(comment.CommentId, Content.Comments.ContentTypes.Comment, null);
foreach (var tag in tags)
{
	doc.AddField("tagkeyword", tag.TagName.ToLower());
	doc.AddField("tag", tag.TagName);
}