lint changes

packages/stream_chat_flutter/lib/src/date_divider.dart

@@ -4,15 +4,20 @@ import 'package:stream_chat_flutter/src/stream_chat_theme.dart';
 
 /// It shows a date divider depending on the date difference
 class DateDivider extends StatelessWidget {
-  final DateTime dateTime;
-  final bool uppercase;
 
+  /// Constructor for creating a [DateDivider]
   const DateDivider({
     Key? key,
     required this.dateTime,
     this.uppercase = false,
   }) : super(key: key);
 
+  /// [DateTime] to display
+  final DateTime dateTime;
+
+  /// If text is uppercase
+  final bool uppercase;
+
   @override
   Widget build(BuildContext context) {
     final createdAt = Jiffy(dateTime);
@@ -22,10 +27,10 @@ class DateDivider extends StatelessWidget {
     if (Jiffy(createdAt).isSame(now, Units.DAY)) {
       dayInfo = 'Today';
     } else if (Jiffy(createdAt)
-        .isSame(now.subtract(Duration(days: 1)), Units.DAY)) {
+        .isSame(now.subtract(const Duration(days: 1)), Units.DAY)) {
       dayInfo = 'Yesterday';
     } else if (Jiffy(createdAt).isAfter(
-      now.subtract(Duration(days: 7)),
+      now.subtract(const Duration(days: 7)),
       Units.DAY,
     )) {
       dayInfo = createdAt.EEEE;