set static method

void set({ required String from, required String to, required double rate, })

Sets the rate from one currency to another.

Implementation

static void set({
  required String from,
  required String to,
  required double rate,
}) {
  if (rate <= 0 || !rate.isFinite) {
    throw ArgumentError.value(
      rate,
      'rate',
      'a conversion rate is a positive number',
    );
  }
  _rates[_key(from, to)] = rate;
}