* @return true if the stage was killed by a call to the destroy()-method. false otherwise.
*/
private boolean runGroup() {
CommandLine cmdLine = new CommandLine(java);
cmdLine.addArgument(jvmParameters, false);
cmdLine.addArgument("-cp");
cmdLine.addArgument("${classpath}", false);
cmdLine.addArgument(GroupStarter.class.getCanonicalName());
cmdLine.addArgument(stageGroup.getName());
cmdLine.addArgument("localhost");
cmdLine.addArgument("" + pipelinePort);