Show how a Set-speed command flows through the refined class structure described in Fig. 1.19, moving from a change on the front panel to the required changes on the train:

a. Show it in the form of a collaboration diagram.

b. Show it in the form of a sequence diagram.

controller current-train: integer current-speed: integer current-direction: boolean current-intertia: unsigned-integer operate() issue-command() FIGURE 1.29 Class diagram for the Controller class.