Some comments never hurt anyone

lib/arrival.dart

@@ -13,9 +13,16 @@ class Arrival {
 
   factory Arrival.fromJson(Map<String, dynamic> json) {
     return Arrival(
+      // Arrival Time
       timeOfDay: json['time_of_day'] as String,
+      
+      // Day 1 -> 7 !! Starting from Monday !!
       weekDay: json['week_day'] as int,
+      
+      // Line 1 or 2
       tramLine: json['tram_line'] as int,
+
+      // True -> Raml, False -> Victoria
       direction: json['direction'] as bool,
     );
   }