Returns the results from the `wdiff` command as a string.

  HTML `<ins>` and `<del>` tags will be used instead of the default markings,
  unless *html* is set to `False`.

  If *fold_tags* is set, `<ins>` and `<del>` tags are allowed to span line
  breaks (option `-n` is not used).

  Raises:

    subrocess.CalledProcessError: on any `wdiff` process errors

def generate_wdiff(org_file, new_file, fold_tags=False, html=True):
  """
  Returns the results from the `wdiff` command as a string.

  HTML `<ins>` and `<del>` tags will be used instead of the default markings,
  unless *html* is set to `False`.

  If *fold_tags* is set, `<ins>` and `<del>` tags are allowed to span line
  breaks (option `-n` is not used).

  Raises:

    subrocess.CalledProcessError: on any `wdiff` process errors

  """
  check_for_wdiff()
  cmd = [CMD_WDIFF]
  if html:
    cmd.extend(OPTIONS_OUTPUT)
  if not fold_tags:
    cmd.extend(OPTIONS_LINEBREAK)
  cmd.extend([org_file, new_file])
  proc = sub.Popen(cmd, stdout=sub.PIPE)
  diff, _ = proc.communicate()
  return diff.decode('utf-8')