code: func (c *instanceCache) describeAllInstancesCached(criteria cacheCriteria) (*allInstancesSnapshot, error) {
  	var err error
  	snapshot := c.getSnapshot()
  	if snapshot != nil && !snapshot.MeetsCriteria(criteria) {
  		snapshot = nil
  	}
  
  	if snapshot == nil {
  		snapshot, err = c.describeAllInstancesUncached()
  		if err != nil {
  			return nil, err
  		}
  	} else {
  		klog.V(6).Infof("EC2 DescribeInstances - using cached results")
  	}
  
  	return snapshot, nil
  }
docs: // describeAllInstancesCached returns all instances, using cached results if applicable