new_contents: #!/usr/bin/env python3
  # -*- coding: utf-8 -*-
  #
  # Copyright (C) 2019 ScyllaDB
  #
  #
  # This file is part of Scylla.
  #
  # Scylla is free software: you can redistribute it and/or modify
  # it under the terms of the GNU Affero General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # Scylla is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU General Public License
  # along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
  #
  
  import argparse
  import json
  import matplotlib.pyplot as plt
  
  cmdline_parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
  cmdline_parser.add_argument('results', nargs=1, help='JSON file with full perf_fast_forward results')
  cmdline_parser.add_argument('-o', '--output', help='name of the output file')
  cmdline_parser.add_argument('--histogram', action='store_true', help='plot a histogram of the frag/s results')
  cmdline_parser.add_argument('--histogram-bins-count', default=50, help='number of histogram bins')
  cmdline_parser.add_argument('--histogram-stats', default='frag/s', help='comma-separated list of result statistic to prepare histograms of')
  
  args = cmdline_parser.parse_args()
  
  results = json.loads(open(args.results[0]).read())
  
  if args.histogram:
      histogram_stats = args.histogram_stats.split(',')
  
      stats = results['results']['stats']
  
      dpi = 96
      width = 1200
      height = 400 * len(histogram_stats)
      plt.figure(figsize=(width/dpi, height/dpi), dpi=dpi)
  
      count = 0
      for histogram_stat in histogram_stats:
          values = [stat[histogram_stat] for stat in stats]
  
          count = count + 1
  
          ax = plt.subplot(len(histogram_stats), 1, count)
          if count == 1:
              plt.title(args.results[0])
  
          ax.set_axisbelow(True)
          plt.grid(True)
          plt.ylabel('count')
          plt.xlabel(histogram_stat)
          plt.hist(values, int(args.histogram_bins_count))
  
      if args.output:
          plt.savefig(args.output)
      else:
          plt.show()
  else:
      print('No action chosen. Doing nothing.')
  
subject: add script for analysing full results