isEmail static method
check field is email
Implementation
static bool isEmail(Map<String, dynamic> data, dynamic value, String args) {
RegExp emailRegex = RegExp(
r'^[\w-]+(\.[\w-]+)*@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*(\.[a-zA-Z]{2,})$');
return emailRegex.hasMatch(value.toString());
}