helper.publishEvent("config_updated", "node2@host2", "web_config");

        assertNotNull(capturedBody.get());
        final Map<String, Object> body = coordinatorHelper.parseJson(capturedBody.get());
        assertEquals("event", body.get("type"));
        assertEquals("config_updated", body.get("name"));
        assertEquals("node1@host1", body.get("instanceId"));
        assertEquals("node2@host2", body.get("targetInstanceId"));

    // Non-exhaustive tests because implementation is the same as resolve.
    val base = parse("http://host/a/b")
    assertThat(base.newBuilder("https://host2")!!.build())
      .isEqualTo(parse("https://host2/"))
    assertThat(base.newBuilder("//host2")!!.build())
      .isEqualTo(parse("http://host2/"))
    assertThat(base.newBuilder("/path")!!.build())
      .isEqualTo(parse("http://host/path"))
    assertThat(base.newBuilder("path")!!.build())