permille method
Converts a number into a per mille string. The number is multiplied by 1000 and a '‰' sign is appended.
Implementation
String permille({int fixed = 2, bool fit = false}) {
String formatted = (this * 1000).toStringAsFixed(fixed);
if (fit) {
formatted = formatted.replaceAll(RegExp(r'\.[0]+$'), '');
}
return '$formatted‰';
}