code: function(el, fn) {
  	  	if(!el || el === document) {
  	  		return false;
  	  	}
  
  	  	// don't search elements above pswp__scroll-wrap
  	  	if(el.getAttribute('class') && el.getAttribute('class').indexOf('pswp__scroll-wrap') > -1 ) {
  	  		return false;
  	  	}
  
  	  	if( fn(el) ) {
  	  		return el;
  	  	}
  
  	  	return _closestElement(el.parentNode, fn);
  	}
docs: amount of pixels to drag to determine direction of swipe