@type t() :: %BexioApiClient.Purchase.PurchaseOrder{
  api_reference: String.t() | nil,
  bank_account_id: integer() | nil,
  compact_view?: boolean() | nil,
  contact_address_manual: String.t() | nil,
  contact_id: integer() | nil,
  contact_sub_id: integer() | nil,
  created_at: DateTime.t() | nil,
  currency: map() | nil,
  currency_id: integer() | nil,
  custom_translations: map() | nil,
  date_format: String.t() | nil,
  delivery_address_manual: String.t() | nil,
  delivery_address_type: :contact_address | :manual | nil,
  document_nr: String.t() | nil,
  footer: String.t() | nil,
  header: String.t() | nil,
  id: integer() | nil,
  kb_item_status_id: integer() | nil,
  kb_payment_template_id: integer() | nil,
  language: map() | nil,
  language_id: integer() | nil,
  logopaper_id: integer() | nil,
  mail: String.t() | nil,
  mwst_is_net?: boolean() | nil,
  mwst_type: :included | :excluded | :exempt | nil,
  nb_decimals_amount: integer() | nil,
  nb_decimals_price: integer() | nil,
  payment_type_id: integer() | nil,
  positions: map() | nil,
  project_id: integer() | nil,
  reference: String.t() | nil,
  salesman_user_id: integer() | nil,
  show_position_taxes?: boolean() | nil,
  template_slug: String.t() | nil,
  terms_of_payment_text: String.t() | nil,
  title: String.t() | nil,
  total_rounding_difference: float() | nil,
  updated_at: DateTime.t() | nil,
  user_id: integer() | nil,
  valid_from: Date.t() | nil,
  valid_to: Date.t() | nil,
  valid_until: Date.t() | nil,
  viewed_by_client_at: Date.t() | nil
}