code: func WithStemmer(s lingo.Stemmer) ConsOpt {
  	fn := func(p *Tagger) {
  		p.Stemmer = s
  	}
  	return fn
  }
docs: // WithStemmer creates a *Tagger with a stemmer.
  // If no stemmer is passed in, then the stemming will be skipped, and the POSTagger will be less accurate