def successors(self) -> Collection["Phase"]:
    """Returns the phases which may follow the current phase."""
    match self:
      case Phase.READY:
        return (Phase.PRE_ACT, Phase.PRE_OBSERVE)
      case Phase.PRE_ACT:
        return (Phase.POST_ACT,)
      case Phase.POST_ACT:
        return (Phase.UPDATE,)
      case Phase.PRE_OBSERVE:
        return (Phase.POST_OBSERVE,)
      case Phase.POST_OBSERVE:
        return (Phase.UPDATE,)
      case Phase.UPDATE:
        return (Phase.READY,)
      case _:
        raise NotImplementedError()
Returns the phases which may follow the current phase.
concordia/typing/deprecated/entity_component.py