code: public void PrintCollocationStrings(PrintWriter pw){
      //ArrayList<String> strs = new ArrayList<String>();
      for(Collocation c: collocationCollector){
        String cs = c.collocationString;
        pw.println(cs+" ("+(c.span.first()+1)+","+(c.span.second()+1)+")");
      }
    }
docs: Prints the collocations found in this <code>Tree</code> as strings.
  Each is followed by its boundary constituent indices in the original tree.
  <br>Example: <code> throw_up (2,3) </code>
  <br>       <code> came_up_with (7,9) </code>