luhn-generator/update/node_modules/core-js-pure/internals/shared-key.js

A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm

var shared = require('../internals/shared');
var uid = require('../internals/uid');

var keys = shared('keys');

module.exports = function (key) {
  return keys[key] || (keys[key] = uid(key));
};