def get_transition(cls, source_state, target_state):
cls.check_transition(source_state, target_state)
for trans in cls.transitions:
for source in trans.source:
if source.name == source_state and trans.target.name == target_state:
return trans.name
raise ForbiddenTransition()
def __check_transition_between_states_exist(cls, source_state,
target_state):
for trans in cls.transitions:
for source in trans.source:
if source.name == source_state and trans.target.name == target_state:
return
raise ForbiddenTransition()
def __check_state_exists(cls, state):
if state not in cls.states:
raise ForbiddenTransition()