package container

 import "sort"

 
 // History is a convenience type for storing a list of containers,

 // sorted by creation date in descendant order.
 type History []*Container

 // Len returns the number of containers in the history.

 func (history *History) Len() int {
 	return len(*history)
 }
 

 // Less compares two containers and returns true if the second one
 // was created before the first one.

 func (history *History) Less(i, j int) bool {
 	containers := *history

 	return containers[j].Created.Before(containers[i].Created)

 }
 

 // Swap switches containers i and j positions in the history.

 func (history *History) Swap(i, j int) {
 	containers := *history

 	containers[i], containers[j] = containers[j], containers[i]

 }
 

 // sort orders the history by creation date in descendant order.

 func (history *History) sort() {

 	sort.Sort(history)
 }