anchor.diff:  %% This function returns timestamps of previous import and update scans.
   %% It takes into consideration whether it is a FirstRun (first after
   %% start/restart of provider).
  -%%
   %% @end
   %%-------------------------------------------------------------------
   -spec get_previous_sync_timestamps(storage_sync_monitoring(),
  
positive.code: prepare(Timestamp, Values) ->
      [
          {timestamp, Timestamp},
          {values, Values}
      ].
  
  %%%===================================================================
  
negative.code: return_histogram_and_timestamp(SSM, imported_files, minute) ->
      prepare(SSM#storage_sync_monitoring.imported_min_hist);
  return_histogram_and_timestamp(SSM, imported_files, hour) ->
      prepare(SSM#storage_sync_monitoring.imported_hour_hist);
  return_histogram_and_timestamp(SSM, imported_files, day) ->
      prepare(SSM#storage_sync_monitoring.imported_day_hist);
  return_histogram_and_timestamp(SSM, updated_files, minute) ->
      prepare(SSM#storage_sync_monitoring.updated_min_hist);
  return_histogram_and_timestamp(SSM, updated_files, hour) ->
      prepare(SSM#storage_sync_monitoring.updated_hour_hist);
  return_histogram_and_timestamp(SSM, updated_files, day) ->
      prepare(SSM#storage_sync_monitoring.updated_day_hist);
  return_histogram_and_timestamp(SSM, deleted_files, minute) ->
      prepare(SSM#storage_sync_monitoring.deleted_min_hist);
  return_histogram_and_timestamp(SSM, deleted_files, hour) ->
      prepare(SSM#storage_sync_monitoring.deleted_hour_hist);
  return_histogram_and_timestamp(SSM, deleted_files, day) ->
      prepare(SSM#storage_sync_monitoring.deleted_day_hist);
  return_histogram_and_timestamp(SSM, queue_length, minute) ->
      prepare(SSM#storage_sync_monitoring.queue_length_min_hist);
  return_histogram_and_timestamp(SSM, queue_length, hour) ->
      prepare(SSM#storage_sync_monitoring.queue_length_hour_hist);
  return_histogram_and_timestamp(SSM, queue_length, day) ->
      prepare(SSM#storage_sync_monitoring.queue_length_day_hist).
  
  %%-------------------------------------------------------------------
  %% @private
  