Question: A problem in testing interactive systems is to anticipate all unexpected behaviour the use

Question: A problem in testing interactive systems is to anticipate all unexpected behaviour the users may do. Consider the SATM system discussed in our lectures and make a list of at least 10 unexpected user behavior that might be observed in practice. (One example of such behavior is when a customer enters 3 digits for the pin code and then leaves.) Then explain how these unexpected behaviours can be tested using threads. (for example, when a customer leaves after entering 3 digits for the pin code, how can this be detected and what kind of an action/error report should be expected from the SATM system?)