code: func (c *Cloud) InstanceExistsByProviderID(ctx context.Context, providerID string) (bool, error) {
  	instanceID, err := KubernetesInstanceID(providerID).MapToAWSInstanceID()
  	if err != nil {
  		return false, err
  	}
  
  	request := &ec2.DescribeInstancesInput{
  		InstanceIds: []*string{instanceID.awsString()},
  	}
  
  	instances, err := c.ec2.DescribeInstances(request)
  	if err != nil {
  		return false, err
  	}
  	if len(instances) == 0 {
  		return false, nil
  	}
  	if len(instances) > 1 {
  		return false, fmt.Errorf("multiple instances found for instance: %s", instanceID)
  	}
  
  	state := instances[0].State.Name
  	if *state == ec2.InstanceStateNameTerminated {
  		klog.Warningf("the instance %s is terminated", instanceID)
  		return false, nil
  	}
  
  	return true, nil
  }
docs: // InstanceExistsByProviderID returns true if the instance with the given provider id still exists.
  // If false is returned with no error, the instance will be immediately deleted by the cloud controller manager.