This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

Non-nullable property 'first_id' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'last_id' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Dereference of a possibly null reference.

Dereference of a possibly null reference.

Possible null reference argument for parameter 'item' in 'void List<ChatMessage>.Add(ChatMessage item)'.

Dereference of a possibly null reference.

Possible null reference argument for parameter 'input' in 'string TeamsKnowledgeCollector.StripHTML(string input)'.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.