Overriding an override

gistfile1.js

Ext.define('A', {
    foo: function() {
        console.log('A Foo');
    }
});

Ext.define('B', {
    override: 'A',
    foo: function() {
        console.log('B Foo');
        this.callParent();
    }
});

Ext.define('C', {
    override: 'A',
    foo: function() {
        console.log('C Foo');
        this.callParent();
    }
});

a = new A();
a.foo();

outputs:
C Foo
B Foo
A Foo