TF-4236 Misleading variable name: maxBatches represents batch size, not batch count.

lib/features/base/mixin/batch_set_email_processing_mixin.dart

@@ -40,14 +40,14 @@ mixin BatchSetEmailProcessingMixin on HandleSetErrorMixin, MailAPIMixin {
 
     final maxObjects = getMaxObjectsInSetMethod(session, accountId);
     final totalEmails = emailIds.length;
-    final maxBatches = min(totalEmails, maxObjects);
+    final batchSize = min(totalEmails, maxObjects);
 
     final List<EmailId> updatedEmailIds = List.empty(growable: true);
     final List<SetResponse> listSetResponse = List.empty(growable: true);
 
-    for (int start = 0; start < totalEmails; start += maxBatches) {
+    for (int start = 0; start < totalEmails; start += batchSize) {
       int end =
-          (start + maxBatches < totalEmails) ? start + maxBatches : totalEmails;
+          (start + batchSize < totalEmails) ? start + batchSize : totalEmails;
 
       log('EmailAPI::$debugLabel:emails from ${start + 1} to $end');
 
@@ -73,7 +73,10 @@ mixin BatchSetEmailProcessingMixin on HandleSetErrorMixin, MailAPIMixin {
         SetEmailResponse.deserialize,
       );
 
-      if (setEmailResponse == null) continue;
+      if (setEmailResponse == null) {
+        log('EmailAPI::$debugLabel: Batch from ${start + 1} to $end returned null response');
+        continue;
+      }
 
       final listEmailIds = setEmailResponse.updated?.keys.toEmailIds() ?? [];
       updatedEmailIds.addAll(listEmailIds);

lib/features/email/data/network/email_api.dart

@@ -694,10 +694,10 @@ class EmailAPI with
       );
 
       final listEmailIds = setEmailResponse?.destroyed?.toEmailIds() ?? [];
-      final mapErrors = handleSetResponse([setEmailResponse]);
+      final batchErrors = handleSetResponse([setEmailResponse]);
 
       destroyedEmailIds.addAll(listEmailIds);
-      mapErrors.addAll(mapErrors);
+      mapErrors.addAll(batchErrors);
     }
 
     return (emailIdsSuccess: destroyedEmailIds, mapErrors: mapErrors);

lib/features/email/domain/exceptions/email_exceptions.dart

@@ -24,4 +24,4 @@ class NotParsableBlobIdToEmailException implements Exception {
   NotParsableBlobIdToEmailException({this.ids});
 }
 
-class EmailIdListIsEmptyException implements Exception {}
+class EmailIdsSuccessIsEmptyException implements Exception {}

lib/features/email/domain/usecases/add_a_label_to_a_thread_interactor.dart

@@ -37,7 +37,7 @@ class AddALabelToAThreadInteractor {
         ));
       } else if (result.emailIdsSuccess.isEmpty) {
         yield Left(AddALabelToAThreadFailure(
-          exception: EmailIdListIsEmptyException(),
+          exception: EmailIdsSuccessIsEmptyException(),
           labelDisplay: labelDisplay,
         ));
       } else {

lib/features/email/domain/usecases/labels/remove_a_label_from_a_thread_interactor.dart

@@ -37,7 +37,7 @@ class RemoveALabelFromAThreadInteractor {
         ));
       } else if (result.emailIdsSuccess.isEmpty) {
         yield Left(RemoveALabelFromAThreadFailure(
-          exception: EmailIdListIsEmptyException(),
+          exception: EmailIdsSuccessIsEmptyException(),
           labelDisplay: labelDisplay,
         ));
       } else {

lib/features/thread_detail/presentation/extension/labels/add_label_to_thread_extension.dart

@@ -49,7 +49,7 @@ extension AddLabelToThreadExtension on ThreadDetailController {
   }
 
   void toggleLabelToThread(
-    Label label,{
+    Label label, {
     required bool isSelected,
     List<EmailId>? currentEmailIds,
   }) {