private void doStopInProcess() {
    cache.close();
    cache = null;
    if (process != null) {
      process.stop(deletePidFileOnStop);
      process = null;
    }
  }
Invokes the 'stop' command and operation to stop a Geode server (a cache server).

@return a {@link ServerState} representing the state of the server following the attempt to
        stop
geode-core/src/main/java/org/apache/geode/distributed/ServerLauncher.java