languageAlpha1ToAlpha3 static method
Return the ISO-639 alpha3 equivalent language code
for the given ISO 639 alpha1 language code.
If the given alpha1 code is not found, this function returns its argument unchanged.
Implementation
static String? languageAlpha1ToAlpha3(String? alpha1) {
return a1toa3langmap[alpha1] ?? alpha1;
}