This chapter was a conglomeration of subjects on testing, Activity management, and advanced conversation techniques. You should become familiar with the Bot Emulator because it offers many features for testing, including message details, logging, and simulating Activities.
The section on Activities went in-depth on Activities other than Messages. You learned how to handle when the user adds a chatbot to their friends list, when a user first communicates, and how to detect when the user is typing. Other Activities include Ping for when a channel wants to know if it can communicate with your chatbot and Typing to let a chatbot know that the user is typing.
Finally, you learned about different ways to send messages other than passively waiting and replying to something the user said. This includes the ability to send a Typing message to the user, sending a message to an existing conversation, and starting a new notification/alert style conversation with the user.