private Properties loadProperties() throws IOException {
    Properties properties = new Properties();
    properties.load(new FileInputStream(propertiesFile));
    assertThat(properties.getProperty(MCAST_PORT)).isEqualTo("0");
    properties.setProperty(MCAST_PORT, "0");
    return properties;
  }
test that the gemfire.properties generated by default is able to start a server
geode-core/src/integrationTest/java/org/apache/geode/distributed/internal/DefaultPropertiesGeneratorIntegrationTest.java