The Exclusive Check-Out Model lets only one user at a time to modify a specific resource. Let's suppose Mary will be the first developer to begin her work. When she opens the
RoomManager.cs file and begins to modify it to implement the GetAllRooms method, by default, Visual Studio will silently try to check it out for editing. If the file isn't already checked out to another user, the operation will succeed and the file can be successfully edited.
Looking at the Output window for Source Control reveals the automatic check-out operation:
In the Solution Explorer window, the Source Control icon changes as we expect to ...