code: function getTranslationForSwipeFraction(element) {
  
    const {
      swipeFraction,
      scrollPullDistance,
      scrollPullMaxReached
    } = element.state;
  
    // When damping, we halve the swipe fraction so the user has to drag twice as
    // far to get the usual damping. This produces the feel of a tighter, less
    // elastic surface.
    let result = swipeFraction ?
      element[symbols.swipeTarget].offsetHeight * dampen(swipeFraction / 2) :
      0;
  
    if (!scrollPullMaxReached && scrollPullDistance) {
      result += scrollPullDistance;
    }
  
    return result;
  }
docs: For a given swipe fraction (percentage of the element's swipe target's height), return the distance of the vertical translation we should apply to the swipe target.