Fix lint

Author: ray2c

lib/common/navigation/page_scaffold.dart

@@ -2,19 +2,25 @@ import 'package:flutter/material.dart';
 
 /// [Scaffold] for pages.
 class PageScaffold extends StatelessWidget {
+  /// The [appBar] to be supplied to [Scaffold].
   final PreferredSizeWidget? appBar;
+  /// The [body] to be supplied to [Scaffold].
   final Widget? body;
+  /// The [drawer] to be supplied to [Scaffold].
   final Widget? drawer;
+  /// The [floatingActionButton] to be supplied to [Scaffold].
   final Widget? floatingActionButton;
+  /// The [floatingActionButtonLocation] to be supplied to [Scaffold].
   final FloatingActionButtonLocation? floatingActionButtonLocation;
 
   /// A [Scaffold] that wraps [body] inside a [SafeArea].
+  /// Meant to be used as a drop-in replacement to [Scaffold] for convenience.
   const PageScaffold({
-    this.appBar = null,
-    this.body = null,
-    this.drawer = null,
-    this.floatingActionButton = null,
-    this.floatingActionButtonLocation = null,
+    this.appBar,
+    this.body,
+    this.drawer,
+    this.floatingActionButton,
+    this.floatingActionButtonLocation,
   });
 
   @override