class TriggerEngine:
    def __init__(self):
        self.agents = []

    def register(self, agent):
        self.agents.append(agent)

    def trigger(self, sender, receiver):
        if sender.can_trigger(receiver):
            return f"{sender.name} aktiviert {receiver.name}"
        else:
            return f"BLOCKIERT: {sender.name} darf {receiver.name} nicht aufrufen"