private static Transition Convert(this TransitionDefinition definition, ParsedStatenode source, Func <OneOf <StatenodeId, string>, ParsedStatenode> getStatenode, ServiceDefinition serviceDefinition, int serviceIndex) =>
definition.Match(
forbidden => new Transition(forbidden.Event, source, Enumerable.Empty <ParsedStatenode>(), Actionblock.Empty(), Option.None <Guard>(), true),
unguarded => new Transition(unguarded.Event.Convert(source, serviceDefinition, serviceIndex), source, unguarded.Targets.GetTargetStatenodes(source.Id, getStatenode), unguarded.Actions.Convert(), Option.None <Guard>(), false),
unguarded => new Transition(unguarded.Event.Convert(source, serviceDefinition, serviceIndex), source, unguarded.Targets.GetTargetStatenodes(source.Id, getStatenode), unguarded.Actions.Convert(), Option.None <Guard>(), false),
unguarded => new Transition(unguarded.Event.Convert(source, serviceDefinition, serviceIndex), source, unguarded.Targets.GetTargetStatenodes(source.Id, getStatenode), unguarded.Actions.Convert(), Option.None <Guard>(), false),
guarded => new Transition(guarded.Event.Convert(source, serviceDefinition, serviceIndex), source, guarded.Targets.GetTargetStatenodes(source.Id, getStatenode), guarded.Actions.Convert(), (guarded.Guard as Guard).ToOption(), false),
guarded => new Transition(guarded.Event.Convert(source, serviceDefinition, serviceIndex), source, guarded.Targets.GetTargetStatenodes(source.Id, getStatenode), guarded.Actions.Convert(), guarded.Guard.AsBase().ToOption(), false),
guarded => new Transition(guarded.Event.Convert(source, serviceDefinition, serviceIndex), source, guarded.Targets.GetTargetStatenodes(source.Id, getStatenode), guarded.Actions.Convert(), guarded.Guard.AsBase().ToOption(), false));