@Test
  public void testEmptySnapshot() {
    final LocatorLoadSnapshot sn = new LocatorLoadSnapshot();
    assertThat(sn.getServerForConnection("group", Collections.emptySet())).isNull();
    assertThat(sn.getServerForConnection(null, Collections.emptySet())).isNull();
    assertThat(sn.getServersForQueue(null, Collections.emptySet(), 5))
        .isEqualTo(Collections.EMPTY_LIST);
  }
Test to make sure than an empty snapshot returns the correct values.
geode-core/src/test/java/org/apache/geode/distributed/internal/LocatorLoadSnapshotTest.java