@type t() :: %Reactor.Executor.State{
  async?: boolean(),
  concurrency_key: Reactor.Executor.ConcurrencyTracker.pool_key(),
  current_tasks: %{required(Task.t()) => Reactor.Step.t()},
  errors: [any()],
  halt_timeout: pos_integer() | :infinity,
  max_concurrency: pos_integer(),
  max_iterations: pos_integer() | :infinity,
  pool_owner: boolean(),
  retries: %{required(reference()) => pos_integer()},
  started_at: DateTime.t(),
  timeout: pos_integer() | :infinity
}