code: def delete_file(dk_api, kitchen, recipe_name, message, files_to_delete_param):
          
          rc = DKReturnCode()
          if kitchen is None or recipe_name is None or message is None or files_to_delete_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_delete_param, basestring):
              files_to_delete = [files_to_delete_param]
          else:
              files_to_delete = files_to_delete_param
          msg = ''
          for file_to_delete in files_to_delete:
              basename = os.path.basename(file_to_delete)
              rc = dk_api.delete_file(kitchen, recipe_name, message, file_to_delete, basename)
              if not rc.ok():
                  msg += '\nDKCloudCommand.delete_file for %s failed\nmessage: %s' % (file_to_delete, rc.get_message())
                  rc.set_message(msg)
                  return rc
              else:
                  msg += 'DKCloudCommand.delete_file for %s succeed' % file_to_delete
          rc.set_message(msg)
          return rc
docs: returns 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_delete_param: path to the files to delete
          :rtype: DKReturnCode