code: final protected BagOfTokens asBagOfTokens(StringWrapper w) 
  	{
  		if (w instanceof BagOfTokens) return (BagOfTokens)w;
  		else {
  			String s = w.unwrap();
  			Token[] toks = tokenizer.tokenize(s);
  			return new BagOfTokens(s,toks);
  		}
  	}
docs: convert to a bag of tokens