private void assertThatPortIsFree(final int port) {
    assertThat(isPortAvailable(port, SOCKET)).isTrue();
  }
Abstract base class for integration tests of both {@link LocatorLauncher} and
{@link ServerLauncher}.

@since GemFire 8.0
geode-core/src/integrationTest/java/org/apache/geode/distributed/LauncherIntegrationTestCase.java