Ext.data.schema.Schema.lookupEntity(): No such Entity

Question

I am creating an ExtJS model using JSNI. But when I try to run the application, it says:

Ext.data.schema.Schema.lookupEntity(): No such Entity "NameValueModel"

NameValueModel is in the same class.

Can you please tell what should I give in schema and Ext.define ?
It should be only the class name or something else?

private native void createModel0() /*-{
    $wnd.Ext.define('NameValueModel', {
        config : {
            name : 'Z',
            value : 0,
        },
        constructor : function(config) {
            this.initConfig(config);
            return this;
        },
        schema : "NameValueModel"
    });
}-*/;