@Test
  @ClearSystemProperty(key = "AvailablePort.lowerBound")
  @ClearSystemProperty(key = "AvailablePort.upperBound")
  @ClearSystemProperty(key = "gemfire.membership-port-range")
  public void testMembershipPortRange() {
    Properties props = new Properties();
    props.setProperty(MCAST_PORT, "0");
    props.setProperty(LOCATORS, "");
    props.setProperty(MEMBERSHIP_PORT_RANGE, "45100-45200");
    DistributionConfig config = createSystem(props).getConfig();
    assertThat(45100).isEqualTo(config.getMembershipPortRange()[0]);
    assertThat(45200).isEqualTo(config.getMembershipPortRange()[1]);
  }
Tests that getting the log level is what we expect.
geode-core/src/integrationTest/java/org/apache/geode/distributed/internal/InternalDistributedSystemIntegrationTest.java