Doesn't seem to work well with "Ext.navigation.view" - Can't extend both class, require only slidenavigation doesn't help

[ghost]

Here is a snippet of my code that's not working: (Here I am extending navigation.view so that I can still "push" panels onto it, instead of extending slidenavigation, I'm just requiring it)

Ext.define('IdMag.view.parents.newsfeed_parent_view', {
//    extend: 'Ext.ux.slidenavigation.View',
    extend: 'Ext.navigation.View',
    xtype: 'newsfeedParentView',
    id: 'newsfeedParentView_id',
    requires: [
    'Ext.ux.slidenavigation.View',
],

But here, the navigation bar works very nicely, but I can't push new panels onto this view though:

Ext.define('IdMag.view.parents.newsfeed_parent_view', {
   extend: 'Ext.ux.slidenavigation.View',
    xtype: 'newsfeedParentView',
    id: 'newsfeedParentView_id',

Did I miss something or is there something else I should be doing?