code: function _haltItemAtFrame(item, perc) {
          item.mod.halt();
          item.halted = true;
          if (item.startSpec && (perc !== undefined)) {
              if ((item.startSpec.opacity !== undefined) && (item.endSpec.opacity !== undefined)) {
                  item.mod.setOpacity(_interpolate(item.startSpec.opacity, item.endSpec.opacity, perc));
              }
              if (item.startSpec.transform && item.endSpec.transform) {
                  var transform = [];
                  for (var i = 0; i < item.startSpec.transform.length; i++) {
                      transform.push(_interpolate(item.startSpec.transform[i], item.endSpec.transform[i], perc));
                  }
                  item.mod.setTransform(transform);
              }
          }
      }
docs: Halts a item at a given frame. The frame is provided as a percentage
  of the whole transition.