code: func (c *Cloud) describeInstances(filters []*ec2.Filter) ([]*ec2.Instance, error) {
  	filters = c.tagging.addFilters(filters)
  	request := &ec2.DescribeInstancesInput{
  		Filters: filters,
  	}
  
  	response, err := c.ec2.DescribeInstances(request)
  	if err != nil {
  		return nil, err
  	}
  
  	var matches []*ec2.Instance
  	for _, instance := range response {
  		if c.tagging.hasClusterTag(instance.Tags) {
  			matches = append(matches, instance)
  		}
  	}
  	return matches, nil
  }
docs: // TODO: Move to instanceCache