code: public Task revertToSnapshot_Task(HostSystem host, Boolean suppressPowerOn) throws VmConfigFault, TaskInProgress, FileFault, InvalidState, InsufficientResourcesFault, RuntimeFault, RemoteException {
          return new Task(getServerConnection(),
              getVimService().revertToSnapshot_Task(getMOR(), host == null ? null : host.getMOR(), suppressPowerOn));
      }
docs: SDK4.0 signature