Hi all,

I'm trying to inherit an Ext.data.Store, and I keep getting an error that

parentPrototype is undefined
 parentStatics = parentPrototype.$inheritableStatics;
in ext-dev.js line 5713

(All references are autoloaded perfectly and they exist afaik)

Code:
Ext.require('Ext.data.Store');
Ext.require('Ext.data.Request');
 
Ext.ns('Lk.store');
Ext.define('Lk.store.SchoolGroupStore', {
    extend    : 'Ext.data.Store',
    singleton : false,
    requires  : ['Lk.model.SchoolGroup'],
    model     : 'Lk.model.SchoolGroup',
    autoLoad: true,
    proxy: {
        type: 'ajax',
        url : '/backoffice/schoolgroup/listEntity',
        reader: {
            type : 'json',
            root : 'rows',
            totalProperty  : 'rowCount',
            successProperty: 'success'
        }
    },
    constructor : function() {
        this.callParent(arguments);
    }
});

Ext.define('Lk.store.SchoolGroupStore2', {
    extend    : 'Lk.store.SchoolGroupStore',
    singleton : true,
    requires  : ['Lk.model.SchoolGroup'],
    model     : 'Lk.model.SchoolGroup',
    autoLoad : true,
    remoteFilter: true,
    proxy: {
        type: 'ajax',
        url : '/backoffice/schoolgroup/listEntity',
        reader: {
            type : 'json',
            root : 'rows',
            totalProperty  : 'rowCount',
            successProperty: 'success'
        }
    },
    constructor : function() {
        this.callParent(arguments);
    }
});
The reason I want to inherit a store is to create a base store with all my default properties, like a common proxi api setting based on the model name:

Code:
Ext.ns('Twensoc.data');
Ext.define('Twensoc.data.BaseStore', {
    extend    : 'Ext.data.Store',
    requires  : ['Ext.data.Store'],
    singleton : false,
    autoLoad: false,
    remoteFilter: true,
    model     : 'Lk.model.SchoolGroup'
    ,
    proxy: {
        type: 'ajax',
        url: 'undefined',
        reader: {
            type : 'json',
            root : 'rows',
            totalProperty  : 'rowCount',
            successProperty: 'success'
        }
    },
    constructor : function() {
            var prefix = this.prefix;
            // derive the proxy api url's based on the modelname
            var modelName = this.model.split(".");
            modelName = modelName[modelName.length-1];
            this.proxy.api = {
                read    : prefix + modelName+'/listEntity',
                create  : prefix + modelName+'/createEntity',
                update  : prefix + modelName+'/saveEntity',
                destroy : prefix + modelName+'/deleteEntity'
            };
            this.callParent(arguments);
        }
    }
});
Am I doing something wrong or overlooking something?

Ronaldo