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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def setup_users_page(self, ):
 """Create and set the model on the users page :returns: None :rtype: None :raises: None """

        self.users_tablev.horizontalHeader().setResizeMode(QtGui.QHeaderView.ResizeToContents)
        log.debug("Loading users for users page.")
        rootdata = treemodel.ListItemData(['Username', 'First', 'Last', 'Email'])
        rootitem = treemodel.TreeItem(rootdata)
        users = djadapter.users.all()
        for usr in users:
            usrdata = djitemdata.UserItemData(usr)
            treemodel.TreeItem(usrdata, rootitem)
        self.users_model = treemodel.TreeModel(rootitem)
        self.users_tablev.setModel(self.users_model)