@Override
      public void run() {
        DistributedSystem system = getSystem();
        assertEquals(member0, system.findDistributedMember("name0"));
        assertEquals(member1, system.findDistributedMember("name1"));
        assertEquals(member2, system.findDistributedMember("name2"));
        assertNull(system.findDistributedMember("name3"));

        Set<DistributedMember> members;
        try {
          members = system.findDistributedMembers(InetAddress.getByName(member0.getHost()));
          HashSet expected = new HashSet();
          expected.add(member0);
          expected.add(member1);
          expected.add(member2);

          // Members will contain the locator as well. Just make sure it has
          // the members we're looking for.
          assertTrue("Expected" + expected + " got " + members, members.containsAll(expected));
          assertEquals(4, members.size());
        } catch (UnknownHostException e) {
          fail("Unable to get IpAddress", e);
        }
      }
The method getId() returns a string that is used as a key identifier in the JMX and Admin APIs.
This test asserts that it matches the expected format. If you change DistributedMember.getId()
or DistributedSystem. getMemberId() you will need to look closely at the format, decide if it
is appropriate for JMX as the id for SystemMember mbeans and then adjust this test as needed.

Changing the id can result in bad keys in JMX and can result in numerous errors in Admin/JMX
tests.
geode-core/src/distributedTest/java/org/apache/geode/distributed/DistributedMemberDUnitTest.java