message: Combine two suggested pip commands into one.
diff: @@ -297,9 +297,8 @@ class TPUClusterResolver(ClusterResolver):
  not _GOOGLE_API_CLIENT_INSTALLED):
  raise ImportError('googleapiclient and oauth2client must be installed '
  'before using the TPU cluster resolver. Execute: '
  - '`pip install --upgrade google-api-python-client` '
  - 'and `pip install --upgrade oauth2client` to '
  - 'install with pip.')
  + '`pip install --upgrade google-api-python-client '
  + 'oauth2client` to install with pip.')
  # We save user-passed credentials, unless the user didn't pass in anything.
  self._credentials = credentials
  