<code>machine = QStateMachine() s1 = QState() s11 = QState(s1) s12 = QState(s1) s1h = QHistoryState(s1) s1h.setDefaultState(s11) machine.addState(s1) s2 = QState() machine.addState(s2) button = QPushButton() # Clicking the button will cause the state machine to enter the child state # that s1 was in the last time s1 was exited, or the history state's default # state if s1 has never been entered. s1.addTransition(button.clicked, s1h)</code>