code: function(view, customIndex){
        var viewCid = view.cid;
  
        // store the view
        this._views[viewCid] = view;
  
        // index it by model
        if (view.model){
          this._indexByModel[view.model.cid] = viewCid;
        }
  
        // index by custom
        if (customIndex){
          this._indexByCustom[customIndex] = viewCid;
        }
  
        this._updateLength();
      }
docs: Add a view to this container. Stores the view by `cid` and makes it searchable by the model cid (and model itself). Optionally specify a custom key to store an retrieve the view.