anchor.diff:  field(Index, DataType, Length, Segment) ->
       ehl7_field:field(Index, DataType, Length, Segment).
   
  -
   -spec field(field_index(), raw_segment()) -> raw_field() | undefined.
   field(Index, Segment) ->
       ehl7_field:field(Index, Segment).
  
positive.code: component(Index, DataType, Length, Segment) ->
      ehl7_field:component(Index, DataType, Length, Segment).
  
  
  -spec component(field_index(), raw_segment()) -> raw_field() | undefined.
  component(Index, Segment) ->
      ehl7_field:component(Index, Segment).
  
negative.code: repetition(Index, DataType, Length, Segment) ->
      ehl7_field:repetition(Index, DataType, Length, Segment).
  
  -spec repetition(field_index(), raw_segment()) -> raw_field() | undefined.
  repetition(Index, Segment) ->
      ehl7_field:repetition(Index, Segment).
  