'Ensure removal of specific notification.'

def test_dismiss_notification(self):

    assert (len(self.hass.states.entity_ids(pn.DOMAIN)) == 0)
    pn.create(self.hass, 'test', notification_id='Beer    2')
    self.hass.block_till_done()
    assert (len(self.hass.states.entity_ids(pn.DOMAIN)) == 1)
    pn.dismiss(self.hass, notification_id='Beer    2')
    self.hass.block_till_done()
    assert (len(self.hass.states.entity_ids(pn.DOMAIN)) == 0)
