format method
Implementation
String format({
Map<TimeSpanUnit, String?>? labels,
String separator = " ",
bool pluralize = true,
bool separateLabel = true,
}) {
labels ??= defaultLabels;
return TimeSpanUnit.values.where((u) => u.get(this).isNotZero).map((unit) {
final value = unit.get(this);
return "$value${separateLabel ? " " : ""}${labels![unit]!.toString().pluralizeIf(value != 1 && pluralize)}";
}).join(" ");
}