docs: def update_file(dk_api, kitchen, recipe_name, message, files_to_update_param):
          """
          reutrns a string.
          :param dk_api: -- api object
          :param kitchen: string
          :param recipe_name: string  -- kitchen name, string
          :param message: string message -- commit message, string
          :param files_to_update_param: string  -- file system directory where the recipe file lives
          :rtype: string
          """
          rc = DKReturnCode()
          if kitchen is None or recipe_name is None or message is None or files_to_update_param is None:
              s = 'ERROR: DKCloudCommandRunner bad input parameters'
              rc.set(rc.DK_FAIL, s)
              return rc
  
          # Take a simple string or an array
          if isinstance(files_to_update_param, basestring):
              files_to_update = [files_to_update_param]
          else:
              files_to_update = files_to_update_param
  
          msg = ''
          for file_to_update in files_to_update:
              try:
                  with open(file_to_update, 'r') as f:
                      file_contents = f.read()
              except IOError as e:
                  if len(msg) != 0:
                      msg += '\n'
                  msg += '%s' % (str(e))
                  rc.set(rc.DK_FAIL, msg)
                  return rc
              except ValueError as e:
                  if len(msg) != 0:
                      msg += '\n'
                  msg += 'ERROR: %s' % e.message
                  rc.set(rc.DK_FAIL, msg)
                  return rc
              rc = dk_api.update_file(kitchen, recipe_name, message, file_to_update, file_contents)
              if not rc.ok():
                  if len(msg) != 0:
                      msg += '\n'
                  msg += 'DKCloudCommand.update_file for %s failed\n\tmessage: %s' % (file_to_update, rc.get_message())
                  rc.set_message(msg)
                  return rc
              else:
                  if len(msg) != 0:
                      msg += '\n'
                  msg += 'DKCloudCommand.update_file for %s succeeded' % file_to_update
  
          rc.set_message(msg)
          return rc