func IsISOCountryCode(in string) bool {
	in = strings.ToUpper(in)
	_, ok := countries[in]
	return ok
}
func IsISOCountryCode(in string) bool {
	in = strings.ToUpper(in)
	_, ok := countries[in]
	return ok
}
func IsISOCountryCode ( in string ) bool { in = strings . ToUpper ( in ) _ , ok := countries [ in ] return ok }
// IsISOCountryCode returns true if the input is a known two-letter country
// code.
//
// TODO: Document where the list of known countries came from.
IsISOCountryCode returns true if the input is a known two - letter country code . TODO : Document where the list of known countries came from .