code: func (ve *VideoExtractor) GetVideos(doc *goquery.Document) *set.Set {
  	var nodes *goquery.Selection
  	for _, videoTag := range videoTags {
  		tmpNodes := doc.Find(videoTag)
  		if nodes == nil {
  			nodes = tmpNodes
  		} else {
  			nodes.Union(tmpNodes)
  		}
  	}
  
  	nodes.Each(func(i int, node *goquery.Selection) {
  		tag := node.Get(0).DataAtom.String()
  		var movie video
  		switch tag {
  		case "video":
  			movie = ve.getVideoTag(node)
  		case "embed":
  			movie = ve.getEmbedTag(node)
  		case "object":
  			movie = ve.getObjectTag(node)
  		case "iframe":
  			movie = ve.getIFrame(node)
  		}
  
  		if movie.src != "" {
  			ve.movies.Add(movie)
  		}
  	})
  
  	return ve.movies
  }
docs: // GetVideos returns the video tags embedded in the article