anchor.diff:  	instance(T, Acc#product_instance{characteristics = NewChars});
   instance([{"productOffering", {struct, Offer}} | T], Acc) ->
   	instance(T, Acc#product_instance{product = product({struct, Offer})});
  +instance([{"status", Status} | T], Acc) ->
  +	instance(T, Acc#product_instance{status = product_status(Status)});
  +instance([{"startDate", SDate} | T], Acc) ->
  +	instance(T, Acc#product_instance{start_date = ocs_rest:iso8601(SDate)});
  +instance([{"terminationDate", TDate} | T], Acc) ->
  +	instance(T, Acc#product_instance{termination_date = ocs_rest:iso8601(TDate)});
   instance([_ | T], Acc) ->
   	instance(T, Acc);
   instance([], Acc) ->
  
positive.code: instance([characteristics | T], #product_instance{characteristics = Chars} = ProductInstance, Acc) ->
  	Characteristics = {"characteristics", characteristics(Chars)},
  	instance(T, ProductInstance, [Characteristics | Acc]);
  instance([_ | T], ProductInstance, Acc) ->
  	instance(T, ProductInstance,  Acc);
  instance([], _ProductInstance, Acc) ->
  
negative.code: -export([get_category/2, get_categories/1]).
  -export([get_product_spec/2, get_product_specs/1]).
  -export([delete_product_offering/1]).
  
  -export([inventory/1]).
  
  -include("ocs.hrl").
  
  