code: function _getTransferable(item, view, id) {
          // 1. If view supports getTransferable, use that
          if (view.getTransferable) {
              return view.getTransferable(id);
          }
          // 2. If view is derived from layoutcontroller, use that
          if (view.getSpec && view.get && view.replace) {
              if (view.get(id) !== undefined) {
                  return {
                      get: function() {
                          return view.get(id);
                      },
                      show: function(renderable) {
                          view.replace(id, renderable);
                      },
                      getSpec: _getViewSpec.bind(this, item, view, id)
                  };
              }
          }
          // 3. If view has an embedded layout, use that as fallback
          if (view.layout) {
              return _getTransferable.call(this, item, view.layout, id);
          }
      }
docs: Gets the transferable delegate for the given id.