Modify the network application for therapy discussed in this chapter so that it handles multiple clients. Each client has its own doctor object. The program saves the doctor object for a client when...

Modify the network application for therapy discussed in this chapter so that it handles multiple clients. Each client has its own doctor object. The program saves the doctor object for a client when it disconnects. Each doctor object should be associated with a patient user name. When a new patient logs in, a new doctor is created. But when an existing patient logs in, its doctor object is read from a file having that patient’s user name. Each doctor object should have its own history list of a patient’s inputs for generating replies that refer to earlier conversations.