text: #!/usr/bin/env python
  
  import argparse
  import itertools
  
  import md_testsuite
  
  output_path = u"all.tmp.md"
  
  parser = argparse.ArgumentParser(
      description="Concatenate all input output pairs into a single file.",
      epilog=r"""The output file is: `{output_path}`. It is already gitignored.
  
  The output format is:
  
      # Path
  
      Input
  
      ---
  
      Output
  
      # Path2
  
      ...
  """ % {output_path:output_path},                   # f contains command name.
      formatter_class=argparse.RawTextHelpFormatter, # Keep newlines.
  )
  args = parser.parse_args()
  
  # Clear the output path.
  with open(output_path, "w") as output_file: pass
  for path, input, output in itertools.chain(md_testsuite.io_iterator(),
          md_testsuite.io_iterator_all_engines()):
      with open(output_path, "a") as output_file:
          output_file.write("# {0}\n\n{1}\n\n---\n\n{2}\n\n".format(path, input, output))
  