removeAllNotNumber method
Implementation
String removeAllNotNumber({List<String> exclude = const []}) {
final List<String> valid = kNumbersString.toList()..addAll(exclude);
final StringBuffer buffer = StringBuffer();
for (int i = 0; i < length; i++) {
final String character = this[i];
if (valid.contains(character)) buffer.write(character);
}
return buffer.toString();
}