backbone-baseview.js
function (key, instance) {
            if (key instanceof View) {
                instance = key;
                key = undefined;
            }
            this._addInstance(key, instance);
            return this;
        }
function (key, instance) {
            if (key instanceof View) {
                instance = key;
                key = undefined;
            }
            this._addInstance(key, instance);
            return this;
        }
function ( key , instance ) { if ( key instanceof View ) { instance = key ; key = undefined ; } this . _addInstance ( key , instance ) ; return this ; }
Add a subview instance. If is has a config,
the instance will be associated with that
config. If the config specifies that the
view is a singleton an a view for that
key already exists, it will not be added.
@param {string|number} key
@param {Backbone.View} instance
 
Add a subview instance, without a key.
Since it doesn't have a key, it will
simply be added to the subViews array.
@param {Backbone.View} instance
Add a subview instance . If is has a config the instance will be associated with that config . If the config specifies that the view is a singleton an a view for that key already exists it will not be added .