code: func (cgc *containerGC) removeOldestNSandboxes(sandboxes []sandboxGCInfo, toRemove int) {
  	// Remove from oldest to newest (last to first).
  	numToKeep := len(sandboxes) - toRemove
  	for i := len(sandboxes) - 1; i >= numToKeep; i-- {
  		if !sandboxes[i].active {
  			cgc.removeSandbox(sandboxes[i].id)
  		}
  	}
  }
docs: // removeOldestNSandboxes removes the oldest inactive toRemove sandboxes and
  // returns the resulting slice.