// First, if `pre_event_a_C == std::nullopt`, then there is nothing to
// do: `CommWait` will never be enabled in the empty configuration (at
// least two actions must be executed before)
// First, if `pre_event_a_C == std::nullopt`, then there is nothing to
// do: `CommWait` will never be enabled in the empty configuration (at
// least two actions must be executed before)