Return a treemodel with the levels: project, assettype, asset and reftrack type

        :returns: a treemodel
        :rtype: :class:`jukeboxcore.gui.treemodel.TreeModel`
        :raises: None

def create_asset_model(self, ):
        """Return a treemodel with the levels: project, assettype, asset and reftrack type

        :returns: a treemodel
        :rtype: :class:`jukeboxcore.gui.treemodel.TreeModel`
        :raises: None
        """
        rootdata = treemodel.ListItemData(['Name'])
        rootitem = treemodel.TreeItem(rootdata)
        prjs = djadapter.projects.all()
        for prj in prjs:
            prjdata = djitemdata.ProjectItemData(prj)
            prjitem = treemodel.TreeItem(prjdata, rootitem)
            for atype in prj.atype_set.all():
                atypedata = djitemdata.AtypeItemData(atype)
                atypeitem = treemodel.TreeItem(atypedata, prjitem)
                for asset in atype.asset_set.filter(project=prj):
                    assetdata = djitemdata.AssetItemData(asset)
                    assetitem = treemodel.TreeItem(assetdata, atypeitem)
                    for typ in self.refobjinter.get_available_types_for_scene(asset):
                        typdata = treemodel.ListItemData([typ])
                        treemodel.TreeItem(typdata, assetitem)

        return treemodel.TreeModel(rootitem)