const oldReflect = this.Reflect;
const oldHTMLElement = this.HTMLElement;

try {
  // Pretend that `Reflect.construct` isn't supported.
  this.Reflect = undefined;

  this.HTMLElement = function() {
    // Here, `this.HTMLElement` is this function, not the original HTMLElement
    // constructor. `this.constructor` should be this function too, but isn't.
    constructor = this.constructor;
  };

  var constructor;

  class CustomElement extends HTMLElement {};
  new CustomElement();

  expect(constructor).toBe(CustomElement);
} finally {
  // Restore original env
  this.Reflect = oldReflect;
  this.HTMLElement = oldHTMLElement;
}