@type t() :: %Ecspanse.Server.State{
  await_systems: [reference()],
  batch_systems: [[Ecspanse.System.t()]],
  delta: non_neg_integer(),
  ecs_version: non_neg_integer(),
  ecspanse_module: module(),
  events_ets_table: atom(),
  fps_limit: non_neg_integer(),
  frame_data: Ecspanse.Frame.t(),
  frame_end_systems: [Ecspanse.System.t()],
  frame_start_systems: [Ecspanse.System.t()],
  frame_timer: :running | :finished,
  last_frame_monotonic_time: integer(),
  scheduled_systems: [Ecspanse.System.t()],
  shutdown_systems: [Ecspanse.System.t()],
  startup_resources: [Ecspanse.Resource.resource_spec()],
  startup_states: [Ecspanse.State.state_spec()],
  startup_systems: [Ecspanse.System.t()],
  status:
    :startup_systems
    | :frame_start_systems
    | :batch_systems
    | :frame_end_systems
    | :all_systems_run
    | :frame_ended,
  system_modules: MapSet.t(module()),
  system_run_conditions_map: map(),
  test: boolean(),
  test_pid: pid() | nil
}