def BackendsUpdate(self):
    """Updates a backend."""
    self.backend = None
    if len(self.args) == 1:
      self.backend = self.args[0]
    elif 1 > len(self.args):
      self.parser.error('Expected an optional <backend> argument.')
    if JavaSupported() and appcfg_java.IsWarFileWithoutYaml(self.basepath):
      java_app_update = appcfg_java.JavaAppUpdate(self.basepath, self.options)
      self.options.compile_jsps = True
      sdk_root = os.path.dirname(appcfg_java.__file__)
      basepath = java_app_update.CreateStagingDirectory(sdk_root)
    else:
      basepath = self.basepath

    yaml_file_basename = 'app'
    appyaml = self._ParseAppInfoFromYaml(basepath,
                                         basename=yaml_file_basename)
    BackendsStatusUpdate(appyaml.runtime, self.error_fh)
    self.BackendsPhpCheck(appyaml)
    rpcserver = self._GetRpcServer()

    backends_to_update = self.BackendsYamlCheck(basepath, appyaml, self.backend)
    for backend in backends_to_update:
      self.UpdateVersion(rpcserver, basepath, appyaml, yaml_file_basename,
                         backend=backend)
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/tools/appcfg.py/AppCfgApp.BackendsUpdate/swapped operands of `>`