code: function (key, instances) {
              if (isArray(key)) {
                  instances = key;
                  key = undefined;
              }
              var i = -1;
              var len = instances.length;
              while (++i < len) {
                  this._addInstance(key, instances[i]);
              }
              return this;
          }
docs: Add a subview for each view instance in
  an array for a particular key
  @memberOf SubViewManager#
  @param {string} key
  @param {Backbone.View[]} instances
  @return {SubViewManager}
   
  Add a subview for each view instance in
  an array. They will not be associated
  with a key and will be only accessible
  through the subViews array.
  @memberOf SubViewManager#
  @param {Backbone.View[]} instances
  @return {SubViewManager}