code: function ElementCollection (elems, context) {
      var elements = nodeListToArray(elems);
      this.context = context;
      this.toArray = function() { return elements; };
  
      this.length = elements.length;
      this.first = elements[0];
      this.last = elements[elements.length-1];
  
      this.get = function(index) {
        if (index === void 0) return elements;
        return elements[index];
      };
    }
docs: ElementCollection contains the result of calling OTHelpers.  It has the following properties: length first last  It also has a get method that can be used to access elements in the collection  var videos = OTHelpers('video'); var firstElement = videos.get(0);               // identical to videos.first var lastElement = videos.get(videos.length-1);  // identical to videos.last var allVideos = videos.get();   The collection also implements the following helper methods: some, forEach, map, filter, find, appendTo, after, before, remove, empty, attr, center, width, height, addClass, removeClass, hasClass, toggleClass, on, off, once, observeStyleChanges, observeNodeOrChildNodeRemoval  Mostly the usage should be obvious. When in doubt, assume it functions like the jQuery equivalent.