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export const regionalIndicatorOfLetter = (char: string) => {
if (char.length !== 1) {
throw new Error("Must be a single character");
}
if (char < "A" || char > "Z") {
throw new Error("Must be A-Z");
}
return char.charCodeAt(0) - "A".charCodeAt(0) +
@jdan.regionalIndicatorA;
};