Is it okay to leave this select_and_confirm() method for now, RD is trying to fix that part, Bug 974828, the elements might be changed again, and I found that if I do this, wait_for_element_present is still raise NoSuchElementException, even if it ignores that in code.

_confirm_suspended_locator = (By.CSS_SELECTOR, '.modal-dialog-confirm-ok')
self.wait_for_element_present(*self._confirm_suspended_locator)
if self.wait_for_element_displayed(*self._confirm_suspended_locator):
    self.marionette.find_element(*self._confirm_suspended_locator).click()