Imports of package checkpoint

PathSynopsis
contextPackage context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes.
github.com/docker/docker/api/server/httputils
github.com/docker/docker/api/server/router
github.com/docker/docker/api/types/checkpoint
net/httpPackage http provides HTTP client and server implementations.