anchor.diff:      var json = {'type': 'Feature'};
       var geometry = {'type': 'Point',
                       'coordinates': [longitude, latitude]};
  -    var properties = {'description': name};
  +    var properties = {'description': name, 'marker-size': 'small'};
   
       if (visitedBy != null) {
         properties['visited by'] = visitedBy.name;
  
positive.code:  * A city that has been visited.
   */
  class City implements Comparable {
    // TODO: marker-size
    // TODO: trips/visits
    String locality;
    String country;
    double longitude;
  
negative.code:     if (livedHere == true) {
        properties['lived here'] = true;
        properties['marker-symbol'] = 'building';
        properties['marker-size'] = 'medium';
      }
  
      json['geometry'] = geometry;
  