public static JsonNode getHostLifePacket() {
        var jsonMapper = Jackson.mapper();
        ObjectNode jsonObject = jsonMapper.createObjectNode();
        jsonObject.put("timestamp", Instant.now().getEpochSecond());
        jsonObject.put("application", "host_life");
        ObjectNode metrics = jsonMapper.createObjectNode();
        metrics.put("alive", 1);
        jsonObject.set("metrics", metrics);
        ObjectNode dimensions = jsonMapper.createObjectNode();
        dimensions.put("vespaVersion", Vtag.currentVersion.toFullString());
        jsonObject.set("dimensions", dimensions);
        return jsonObject;
    }
@Test
    void host_is_alive() {
        JsonNode packet = HostLifeGatherer.getHostLifePacket();
        JsonNode metrics = packet.get("metrics");
        assertEquals("host_life", packet.get("application").textValue());
        assertEquals(1, metrics.get("alive").intValue());
        assertTrue(packet.get("dimensions").hasNonNull("vespaVersion"));
    }