credentials() :: %{user: String.t(), password: String.t(), endpoint: String.t()}

t() :: %{
  hotel_code: String.t(),
  rule_messages: [
    %{
      status_application_control: %{
        start: String.t(),
        end: String.t(),
        inv_type_code: String.t(),
        rate_plan_code: String.t(),
        destination_system_codes: [integer()]
      },
      booking_rules: [
        %{
          lengths_of_stay:
            [
              %{
                time: String.t(),
                time_unit: String.t(),
                min_max_message_type: String.t()
              }
            ]
            | nil,
          restriction_status:
            %{restriction: String.t(), status: String.t()} | nil
        }
      ]
    }
  ]
}