checkpoint              Configures R session to use packages as they
                        existed on CRAN at time of snapshot.
checkpoint-package      Install packages from snapshots on the
                        checkpoint server for reproducibility
checkpointArchives      List checkpoint archives on disk.
checkpointRemove        Remove checkpoint archive from disk.
getValidSnapshots       Read list of available snapshot dates from MRAN
                        url.
setSnapshot             Set default CRAN repository to MRAN snapshot
                        date.
