@type t() :: %Procore.Model.BillingPeriod{
  created_at: DateTime.t() | nil,
  due_date: Date.t() | nil,
  end_date: Date.t() | nil,
  id: integer() | nil,
  position: integer() | nil,
  project_id: integer() | nil,
  start_date: Date.t() | nil,
  status: String.t() | nil,
  updated_at: DateTime.t() | nil
}