docs: def version(command='dmenu'):
      '''The dmenu command's version message.
  
      Raises:
          DmenuCommandError
  
      Example:
  
          >>> import dmenu
          >>> dmenu.version()
          'dmenu-4.5, \xc2\xa9 2006-2012 dmenu engineers, see LICENSE for details'
      '''
  
      args = [command, '-v']
  
      try:
          # start the dmenu process
          proc = subprocess.Popen(
              args,
              universal_newlines=True,
              stdout=subprocess.PIPE,
              stderr=subprocess.PIPE)
      except OSError as err:
          # something went wrong with starting the process
          raise DmenuCommandError(args, err)
  
      if proc.wait() == 0:
          # version information from stdout
          return proc.stdout.read().rstrip('\n')
  
      # error from dmenu
      raise DmenuCommandError(args, proc.stderr.read())