@type t() :: %WplAi.AST.Document{
  athlete_thresholds: AthleteThresholds.t() | nil,
  goals: [Goal.t()] | nil,
  habits: [PlanHabit.t()] | nil,
  header: Header.t(),
  meta: map(),
  notifications: [Notification.t()] | nil,
  personalization: Personalization.t() | nil,
  phases: [Phase.t()],
  progress: Progress.t() | nil,
  rendering: Rendering.t() | nil,
  requirements: Requirements.t() | nil
}