@type t() :: %Riichi.Event.RoundStart{
  bonus_sticks: non_neg_integer() | nil,
  dealer: Riichi.Actor.t() | nil,
  dora_indicators: [Riichi.Tile.t()] | nil,
  hands: %{required(Riichi.Actor.t()) => Riichi.Hand.t() | :unknown} | nil,
  riichi_bets: non_neg_integer() | nil,
  round_id: non_neg_integer() | nil,
  scores: %{required(Riichi.Actor.t()) => integer()} | nil,
  wall: (tuple() | :unknown) | nil
}