anchor.diff:    
     @override
     Future close() {
  -    return _conn.close().then((_) {
  -      _conn = null;
  -    });
  +    return new Future.value(null);
     }
   }
   
  
positive.code: 
      cursor.skip = skip;
      cursor.limit = limit;
          
      return cursor.stream.asyncMap((m) {
        if(!_known.containsKey(m["_id"])) {
          var obj = _dty.mirror.newInstance(#revive, [m]).reflectee;
  
negative.code:       } else {
          // Explicitly *DONT* override members here to avoid clobbering unsaved
          // changes
          return _known[m["_id"]];
        }
      });
  