if (properties == null) {   properties = (Properties) Runtime.defaultProperties.clone(); } System.properties = properties;
SystemProperties.setProperties(properties);
  public static void setProperties(Properties properties)  {    SecurityManager sm = Runtime.securityManager; // Be thread-safe.    if (sm != null)      sm.checkPropertiesAccess();    if (properties == null)      {	// Note that we use clone here and not new.  Some programs	// assume that the system properties do not have a parent.	properties = (Properties) Runtime.defaultProperties.clone();      }    System.properties = properties;    }