@type t() :: %Riichi.Event.RoundEnd{
  from_actor: (Riichi.Actor.t() | nil) | nil,
  hands:
    %{required(Riichi.Actor.t()) => Riichi.Event.RoundEnd.ReadyHand.t()} | nil,
  kind:
    (:ron | :tsumo | :exhaustive_draw | {:abort, Riichi.Event.abort_kind()})
    | nil,
  points_delta: %{required(Riichi.Actor.t()) => integer()} | nil,
  wins: %{required(Riichi.Actor.t()) => Riichi.Scoring.t()} | nil
}