@Test
  public void testFailedCheckIfAvailableWithoutFailureDetectionPortRemovesMember()
      throws Exception {
    useGMSHealthMonitorTestClass = true;
    simulateHeartbeatInGMSHealthMonitorTestClass = false;

    final long checkRequestsSentBefore = services.getStatistics().getUdpFinalCheckRequestsSent();

    GMSMembershipView v = installAView();

    MemberIdentifier memberToCheck = gmsHealthMonitor.getNextNeighbor();
    boolean available = gmsHealthMonitor.checkIfAvailable(memberToCheck, "Not responding", true);

    assertFalse(available);
    verify(joinLeave).remove(isA(MemberIdentifier.class), isA(String.class));

    final long checkRequestsSentAfter = services.getStatistics().getUdpFinalCheckRequestsSent();
    assertThat(checkRequestsSentAfter).isGreaterThan(checkRequestsSentBefore);
  }
Same test as above but with request to initiate removal
geode-membership/src/integrationTest/java/org/apache/geode/distributed/internal/membership/gms/fd/GMSHealthMonitorJUnitTest.java