isValidUKPostCode method
Checks the object is a String and is a valid UK post code
Implementation
AbstractRuleBuilder isValidUKPostCode({String? message}) {
return must(
(dynamic dyn) =>
dyn is String && CommonRegex.postCodeValidator.hasMatch(dyn),
message != null
? message
: useKeyAsElementName
? "$key must be a valid UK post code"
: "String must be a valid UK post code",
code: "notWalidUKPostCode");
}