code: function toAlpha2(code) {
    if (typeof code === "string") {
      if (/^[0-9]*$/.test(code)) {
        return numericToAlpha2(code);
      }
      if (code.length === 2) {
        return code.toUpperCase();
      }
      if(code.length === 3) {
        return alpha3ToAlpha2(code.toUpperCase());
      }
    }
    if (typeof code === "number") {
      return numericToAlpha2(code);
    }
    return undefined;
  }
docs: /*
  @param code ISO 3166-1 alpha-2, alpha-3 or numeric code
  @return ISO 3166-1 alpha-2