Function subClass

src/polyfills/custom-elements.js:796–808

* Setups up prototype inheritance * * @param {!SUPER} superClass * @param {!SUB} subClass * @template SUPER * @template SUB

(superClass, subClass)

 * @template SUB
 */
function subClass(superClass, subClass) {
  // Object.getOwnPropertyDescriptor(superClass.prototype, 'constructor')
  // {value: ƒ, writable: true, enumerable: false, configurable: true}
  subClass.prototype = Object.create(superClass.prototype, {
    constructor: {
      // enumerable: false,
      configurable: true,
      writable: true,
      value: subClass,
    },
  });
  setPrototypeOf(subClass, superClass);
}

/**
 * Tests whether setting '__proto__' will change the prototype chain of an