tryFormat method
If value is not null - formats the value as a string with
the currency symbol. Otherwise returns null.
When isRtl is true, the unit position is flipped to ensure correct
display in right-to-left locales.
Implementation
// This is limitation of Dart language + breaking change.
// ignore: avoid_positional_boolean_parameters, prefer-named-boolean-parameters
String? tryFormat([num? maybeValue, bool isRtl = false]) =>
maybeValue == null ? null : format(maybeValue, isRtl: isRtl);