anchor.diff:  	FilteredPrices2 = filter_prices_key(ChargingKey, FilteredPrices1),
   	FilteredPrices3 = filter_prices_tod(Timestamp, FilteredPrices2),
   	case filter_prices_dir(Direction, FilteredPrices3) of
  +		[#price{type = #pla_ref{}} = Price | _] ->
  +			 {pla_ref, Price};
   		[#price{units = Units, type = PriceType, size = UnitSize, amount = UnitPrice,
   				currency = Currency, char_value_use = PriceChars} = Price | _] ->
   			RoamingTable = roaming_table_prefix(Price),
  
positive.code: 				| {out_of_credit, RedirectServerAddress, SessionList}
  				| {out_of_credit, RedirectServerAddress, SessionList, Rated}
  				| {disabled, SessionList}
  				| {error, Reason},
  		Service :: #service{},
  		GrantedAmount :: {Type, Amount},
  		Rated :: [#rated{}],
  
negative.code: 		ChargingKey, Flag, DebitAmounts,
  		ReserveAmounts, SessionAttributes)
  		when ((Protocol == radius) or (Protocol == diameter)),
  		is_binary(SubscriberID),
  		(is_integer(ChargingKey) or (ChargingKey == undefined)),
  		(is_integer(ServiceId) or (ServiceId== undefined)),
  		(is_integer(UnitSize) or (UnitSize == undefined)),
  		(is_integer(UnitPrice) or (UnitPrice == undefined)),
  		(is_integer(Units) or (Units == undefined)),
  