anchor.diff:  		case ocs:add_offer(offer(mochijson:decode(ReqData))) of
   			{ok, ProductOffering} ->
   				ProductOffering;
  +			{error, Reason} ->
   			{error, Reason} ->
   				throw(Reason)
   		end
  
positive.code: 			case global:whereis_name(Etag) of
  				undefined ->
  					{error, 412};
  				PageServer ->
  					case ocs_rest:range(Range) of
  						{error, _} ->
  							{error, 400};
  						{ok, {Start, End}} ->
  							query_page(Codec, PageServer, Etag, Query, Filters, Start, End)
  
negative.code: inventory(ProductInstance) ->
  	{struct, inventory(record_info(fields, product), ProductInstance, [])}.
  %% @hidden
  inventory([{"id", Id} | T], Acc) when is_list(Id) ->
  	inventory(T, Acc#product{id = Id});
  inventory([{"characteristic", Chars} | T], Acc) ->
  	inventory(T, Acc#product{characteristics = instance_chars(Chars)});
  inventory([{"productOffering", {struct, Offer}} | T], Acc) ->
  