The constructor creates a Touch/TouchEvent object from an init dictionary like other event types, also able to initialize UIEvent fields. More favorable than the old "document.create... + e.init..." way.
Docs: https://developer.mozilla.org/en-US/docs/Web/API/Touch/Touch https://developer.mozilla.org/en-US/docs/Web/API/TouchEvent/TouchEvent
Samples: https://jsbin.com/lohuwa