code: function(element, callback) {
          resolveElementHeightChange(element).then(function(newVal, oldVal) {
              var heightEvent = jQuery.Event('timelineMe.itemHeightChanged', {elementHeight: newVal, previousHeight: oldVal});
              element.trigger(heightEvent);
          });
          element.on('timelineMe.itemHeightChanged', function(e) {
              callback({element: element, newVal: e.elementHeight, oldVal: e.previousHeight});
              resolveElementHeightChange($(e.target), {previousHeight: e.elementHeight}).then(function(newVal, oldVal) {
                  var heightEvent = jQuery.Event('timelineMe.itemHeightChanged', {elementHeight: newVal, previousHeight: oldVal});
                  $(e.target).trigger(heightEvent);
              });
          });
      }
docs: Method that can watch for an element's height change (uses the resolveElementHeightChange function)