@Test
  public void testLocatorUpdateIntervalZero() {
    long updateLocatorInterval = 0;
    System.setProperty(GeodeGlossary.GEMFIRE_PREFIX + "LOCATOR_UPDATE_INTERVAL",
        String.valueOf(updateLocatorInterval));
    source.start(pool);
    assertThat(source.getLocatorUpdateInterval()).isEqualTo(updateLocatorInterval);
  }
This tests that discovery works even after one of two locators was shut down
geode-core/src/integrationTest/java/org/apache/geode/cache/client/internal/AutoConnectionSourceImplIntegrationTest.java