HistoryTracker          A reference class for tracking code history
historyTracker          Construct and activate a HistoryTracker object
histropts               histry
knitrtracer             knitr history tracking These functions are
                        exported due to the vagaries of how tracing
                        functions works in R. Knitr history support is
                        now turned on when the histry package is
                        loaded; They should never be called directly by
                        an end user.
