anchor.diff:  									po_price(erlang_term, T, [Price2 | Prices])
   								end
   						end;
  -					true ->
  -						{error, 400};
   				true ->
   					{error, 400}
   			end
  
positive.code: po_alteration(erlang_term, ProdAlterObj) ->
  	try
  		ProdAlterName = prod_price_alter_name(erlang_term, ProdAlterObj),
  		_ProdAlterSTime = prod_price_alter_vf(erlang_term, ProdAlterObj),
  		ProdAlterPriceType = prod_price_alter_price_type(erlang_term, ProdAlterObj),
  		{_, ProdAlterUOMeasure} = lists:keyfind("unitOfMeasure", 1, ProdAlterObj),
  		{_, {struct, ProdAlterPriceObj}} = lists:keyfind("price", 1, ProdAlterObj),
  
negative.code: prod_price_alter_vf(erlang_term, PAlter) ->
  	{_, {struct, PAlterVF}} = lists:keyfind("validFor", 1, PAlter),
  	{_, PAlterSTimeISO} = lists:keyfind("startDateTime", 1, PAlterVF),
  	case lists:keyfind("endDateTime", 1, PAlterVF) of
  		false ->
  			{ocs_rest:timestamp(PAlterSTimeISO), undefined};
  		PAlterETime ->
  			{ocs_rest:timestamp(PAlterSTimeISO), PAlterETime}
  	end;
  prod_price_alter_vf(json, PAlter) ->
  	ValidFor = PAlter#alteration.valid_for,
  	case ValidFor of
  		{SDateTime, undefined} ->
  			SDT = {"startDateTime", ocs_rest:iso8601(SDateTime)},
  			{"ValidFor", {struct, [SDT]}};
  		{SDateTime, EDateTime} ->
  			SDT = {"startDateTime", ocs_rest:iso8601(SDateTime)},
  			EDT = {"endDateTime", ocs_rest:iso8601(EDateTime)},
  			{"ValidFor", {struct, [SDT, EDT]}}
  	end.
  
  -spec prod_price_alter_description(Prefix, PAlter) -> Result
  	when
  