@type t() :: %Spatio.Model.Attendee{
  additional_guests: integer() | nil,
  comment: String.t() | nil,
  email: String.t(),
  name: String.t() | nil,
  optional: boolean(),
  role: Spatio.Model.AttendeeRole.t(),
  status: Spatio.Model.AttendeeStatus.t()
}