@type t() :: %HL7v2.Segment.AIS{
  allow_substitution_code: term(),
  duration: term(),
  duration_units: term(),
  extra_fields: term(),
  filler_status_code: term(),
  filler_supplemental_service_information: term(),
  placer_supplemental_service_information: term(),
  segment_action_code: term(),
  set_id: term(),
  start_date_time: term(),
  start_date_time_offset: term(),
  start_date_time_offset_units: term(),
  universal_service_identifier: term()
}