luhn-generator/update/node_modules/core-js/modules/_an-instance.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

module.exports = function (it, Constructor, name, forbiddenField) {
  if (!(it instanceof Constructor) || (forbiddenField !== undefined && forbiddenField in it)) {
    throw TypeError(name + ': incorrect invocation!');
  } return it;
};