'Ensures the staff lock option is visible, clicking on the advanced tab
if needed.'

def ensure_staff_lock_visible(self):

    if (not self.is_staff_lock_visible):
        self.find_css('.settings-tab-button[data-tab=visibility]').click()
    EmptyPromise((lambda : self.is_staff_lock_visible), 'Staff    lock    option    is    visible').fulfill()
