'Click on a button as specified by `button_name`
Arguments:
button_name (str): button name
index (int): query index'

def click_button(self, button_name, index=0, require_notification=False):

    self.q(css=BUTTON_SELECTORS[button_name]).nth(index).click()
    if require_notification:
        sync_on_notification(self)
    self.wait_for_ajax()
