anchor.diff:    SessionSummary(this.session_id);
   
     void setBoolStat(String statName, bool statValue) {
  +    print("setting stat: $statName to $statValue");
         this.bool_stats[statName] = statValue;
     }
   
  
positive.code: 
  
  
   MultiSessionSummary();
  
    num getNumStat(String statName) {
      num ret = this.num_stats[statName]; //initialization, not error
  
negative.code:     return html;
    }
  
    //todo, could make this a constructor with from, too. whatever.
    static SessionSummary makeSummaryForSession(Session session) {
      SessionSummary summary = new SessionSummary(session.session_id);
      summary.setMiniPlayers(session.players);
  