update total price

lib/domain/product/entities/product_quantity_entity.dart

@@ -6,9 +6,9 @@ class ProductQuantity with _$ProductQuantity {
     required Product product,
     ProductVariant? variant,
     required int quantity,
-    String? notes,
+    required String notes,
   }) = _ProductQuantity;
 
   factory ProductQuantity.empty() =>
-      ProductQuantity(product: Product.empty(), quantity: 0);
+      ProductQuantity(product: Product.empty(), quantity: 0, notes: '');
 }

lib/domain/product/product.freezed.dart

@@ -1097,7 +1097,7 @@ mixin _$ProductQuantity {
   Product get product => throw _privateConstructorUsedError;
   ProductVariant? get variant => throw _privateConstructorUsedError;
   int get quantity => throw _privateConstructorUsedError;
-  String? get notes => throw _privateConstructorUsedError;
+  String get notes => throw _privateConstructorUsedError;
 
   /// Create a copy of ProductQuantity
   /// with the given fields replaced by the non-null parameter values.
@@ -1117,7 +1117,7 @@ abstract class $ProductQuantityCopyWith<$Res> {
     Product product,
     ProductVariant? variant,
     int quantity,
-    String? notes,
+    String notes,
   });
 
   $ProductCopyWith<$Res> get product;
@@ -1142,7 +1142,7 @@ class _$ProductQuantityCopyWithImpl<$Res, $Val extends ProductQuantity>
     Object? product = null,
     Object? variant = freezed,
     Object? quantity = null,
-    Object? notes = freezed,
+    Object? notes = null,
   }) {
     return _then(
       _value.copyWith(
@@ -1158,10 +1158,10 @@ class _$ProductQuantityCopyWithImpl<$Res, $Val extends ProductQuantity>
                 ? _value.quantity
                 : quantity // ignore: cast_nullable_to_non_nullable
                       as int,
-            notes: freezed == notes
+            notes: null == notes
                 ? _value.notes
                 : notes // ignore: cast_nullable_to_non_nullable
-                      as String?,
+                      as String,
           )
           as $Val,
     );
@@ -1205,7 +1205,7 @@ abstract class _$$ProductQuantityImplCopyWith<$Res>
     Product product,
     ProductVariant? variant,
     int quantity,
-    String? notes,
+    String notes,
   });
 
   @override
@@ -1231,7 +1231,7 @@ class __$$ProductQuantityImplCopyWithImpl<$Res>
     Object? product = null,
     Object? variant = freezed,
     Object? quantity = null,
-    Object? notes = freezed,
+    Object? notes = null,
   }) {
     return _then(
       _$ProductQuantityImpl(
@@ -1247,10 +1247,10 @@ class __$$ProductQuantityImplCopyWithImpl<$Res>
             ? _value.quantity
             : quantity // ignore: cast_nullable_to_non_nullable
                   as int,
-        notes: freezed == notes
+        notes: null == notes
             ? _value.notes
             : notes // ignore: cast_nullable_to_non_nullable
-                  as String?,
+                  as String,
       ),
     );
   }
@@ -1265,7 +1265,7 @@ class _$ProductQuantityImpl
     required this.product,
     this.variant,
     required this.quantity,
-    this.notes,
+    required this.notes,
   });
 
   @override
@@ -1275,7 +1275,7 @@ class _$ProductQuantityImpl
   @override
   final int quantity;
   @override
-  final String? notes;
+  final String notes;
 
   @override
   String toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) {
@@ -1326,7 +1326,7 @@ abstract class _ProductQuantity implements ProductQuantity {
     required final Product product,
     final ProductVariant? variant,
     required final int quantity,
-    final String? notes,
+    required final String notes,
   }) = _$ProductQuantityImpl;
 
   @override
@@ -1336,7 +1336,7 @@ abstract class _ProductQuantity implements ProductQuantity {
   @override
   int get quantity;
   @override
-  String? get notes;
+  String get notes;
 
   /// Create a copy of ProductQuantity
   /// with the given fields replaced by the non-null parameter values.