operator - method
numerically subtract operand
from this phone number
e.g.
PhoneParser.parseRaw('61383208100') - 1 == PhoneParser.parseRaw('61383208099');
Implementation
PhoneNumber operator -(int operand) {
final nsnLength = nsn.length;
final resultNsn = BigInt.parse(nsn) - BigInt.from(operand);
return PhoneNumber(
isoCode: isoCode,
nsn: resultNsn.toString().padLeft(nsnLength, '0'),
);
}