code: private boolean checkVmIsStarted() {
  
  		DescribeInstancesRequest dis = new DescribeInstancesRequest();
  		dis.setInstanceIds(Collections.singletonList(this.machineId));
  
  		DescribeInstancesResult disresult = this.ec2Api.describeInstances( dis );
  		// Obtain availability zone (for later use, eg. volume attachment).
  		// Necessary if no availability zone is specified in configuration
  		// (because volumes must be attached to instances in the same availability zone).
  		this.availabilityZone = disresult.getReservations().get(0).getInstances().get(0).getPlacement().getAvailabilityZone();
  		return "running".equalsIgnoreCase( disresult.getReservations().get(0).getInstances().get(0).getState().getName());
  	}
docs: Checks whether a VM is started or not (which is stronger than {@link #checkVmIsKnown()}).
  @return true if the VM is started, false otherwise