phone function
It generates a random phone number.
Args: temp (String): The template to use for the phone number.
Returns: A string of a phone number.
Implementation
String phone([String? temp]) {
String phoneNumber;
if (temp != null) {
phoneNumber = template(temp);
} else {
phoneNumber = (Random().nextInt(99999999) + 1000000000).toString();
}
return phoneNumber;
}