load( [options] )2Loads the Store using its configured proxy.
Available since: Ext 4 Parameters
options : Object (optional)config object. This is passed into the Operation object that is created and then sent to the proxy's Ext.data.proxy.Proxy.read function. The options can also contain a node, which indicates which node is to be loaded. If not specified, it will default to the root node.
But, node option does not work after I upgrade ExtJS to 4.2.0 version.