handleTouchMove_(event) {
    // Due to https://github.com/mpizenberg/elm-pep/issues/2, `this.originalPointerMoveEvent_`
    // may not be initialized yet when we get here on a platform without native pointer events,
    // when elm-pep is used as pointer events polyfill.
    const originalEvent = this.originalPointerMoveEvent_;
    if (
      (!originalEvent || originalEvent.defaultPrevented) &&
      (typeof event.cancelable !== 'boolean' || event.cancelable === true)
    ) {
      event.preventDefault();
    }
  }
Flexible handling of a `touch-action: none` css equivalent: because calling
`preventDefault()` on a `pointermove` event does not stop native page scrolling
and zooming, we also listen for `touchmove` and call `preventDefault()` on it
when an interaction (currently `DragPan` handles the event.
@param {TouchEvent} event Event.
@private