   # Public: Create a pointer to the current state of the buffer for use
   # with {::revertToCheckpoint} and {::groupChangesSinceCheckpoint}.
   #
-  # Returns a checkpoint value.
+  # Returns a checkpoint id value.
   createCheckpoint: ->
     @historyProvider.createCheckpoint(markers: @createMarkerSnapshot(), isBarrier: false)
 

  #
  # If the given checkpoint is no longer present in the undo history, this
  # method will return an empty {Array}.
  #
  # Returns an {Array} of {Object}s with the following fields that summarize
  #  the aggregated changes since the checkpoint. See *Working With Aggregated

  # undo history, no changes will be made to the buffer and this method will
  # return `false`.
  #
  # * `checkpoint` {Number} id of the checkpoint to revert to.
  #
  # Returns a {Boolean} indicating whether the operation succeeded.
  revertToCheckpoint: (checkpoint) ->
    if truncated = @historyProvider.revertToCheckpoint(checkpoint)
      @emitWillChangeEvent()
      @transactCallDepth++
      try
