Store is not available in filters function of the store in Ext JS 5

Question

I am converting ExtJS 4.1.1 app to ExtJS 5. And I am keeping the MVC architecture as it is. I have a store as below, which has 'filters' config. when the store loads filter function is getting called but 'store' object is not available in it. Please reply if you have any clue.

Ext.define('myapp.model.base.KeyValue', {
    extend : 'Ext.data.Model',
    fields : [ {
        name : 'keyCode',
        useNull : true,
    }, {name:'keyValue', type:'string'},'description','isActive' ]
});

Ext.define('myapp.store.base.KeyValueStore', {
    extend: 'Ext.data.Store',
    model: 'myapp.model.base.KeyValue',
    filter: [
        function (item) {
            if (Ext.isDefined(item.data.isActive)) {
                if (Ext.isDefined(item.store.showInactive)&& item.store.showInactive) {
                    return true;
                }
                return item.data.isActive !== false;
            }
            return true;
        }
    ]
});

in the above code item.store.showInactive, 'store' is undefined. May I know why?