'Test the as_timestamp function.'

def test_as_timestamp(self):

    self.assertEqual('None', template.Template('{{    as_timestamp("invalid")    }}', self.hass).render())
    self.hass.mock = None
    self.assertEqual('None', template.Template('{{    as_timestamp(states.mock)    }}', self.hass).render())
    tpl = '{{    as_timestamp(strptime("2024-02-03T09:10:24+0000",    "%Y-%m-%dT%H:%M:%S%z"))    }}'
    self.assertEqual('1706951424.0', template.Template(tpl, self.hass).render())
