def highest_ranked_stems(doc, count = 3)
      raise 'Requested stem ranking on non-indexed content!' unless @items[doc]

      content_vector_array = node_for_content(doc).lsi_vector.to_a
      top_n = content_vector_array.sort.reverse[0..count - 1]
      top_n.collect { |x| @word_list.word_for_index(content_vector_array.index(x)) }
    end
def highest_ranked_stems(doc, count = 3)
      raise 'Requested stem ranking on non-indexed content!' unless @items[doc]

      content_vector_array = node_for_content(doc).lsi_vector.to_a
      top_n = content_vector_array.sort.reverse[0..count - 1]
      top_n.collect { |x| @word_list.word_for_index(content_vector_array.index(x)) }
    end
Prototype, only works on indexed documents.
 I have no clue if this is going to work, but in theory
 it's supposed to.