情境
Checkout is a lifecycle, not a process list: the session can move forward, retry, or terminate depending on events and guards. A composite state keeps the external lifecycle readable while still showing the internal payment substates.
UML statechart for a checkout session with a composite Payment state, entry and exit activities, guards, and retry transitions.
Checkout is a lifecycle, not a process list: the session can move forward, retry, or terminate depending on events and guards. A composite state keeps the external lifecycle readable while still showing the internal payment substates.