1 files changed, 42 insertions, 41 deletions
diff --git a/src/python/grpcio/grpc/_auth.py b/src/python/grpcio/grpc/_auth.py
index dea3221c9d..e8a90cf504 100644
--- a/src/python/grpcio/grpc/_auth.py
+++ b/src/python/grpcio/grpc/_auth.py
@@ -26,7 +26,6 @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
 """GRPCAuthMetadataPlugins for standard authentication."""
 
 import inspect
@@ -36,51 +35,53 @@ import grpc
 
 
 def _sign_request(callback, token, error):
-  metadata = (('authorization', 'Bearer {}'.format(token)),)
-  callback(metadata, error)
+    metadata = (('authorization', 'Bearer {}'.format(token)),)
+    callback(metadata, error)
 
 
 class GoogleCallCredentials(grpc.AuthMetadataPlugin):
-  """Metadata wrapper for GoogleCredentials from the oauth2client library."""
-
-  def __init__(self, credentials):
-    self._credentials = credentials
-    self._pool = futures.ThreadPoolExecutor(max_workers=1)
-
-    # Hack to determine if these are JWT creds and we need to pass
-    # additional_claims when getting a token
-    if 'additional_claims' in inspect.getargspec(
-        credentials.get_access_token).args:
-      self._is_jwt = True
-    else:
-      self._is_jwt = False
-
-  def __call__(self, context, callback):
-    # MetadataPlugins cannot block (see grpc.beta.interfaces.py)
-    if self._is_jwt:
-      future = self._pool.submit(self._credentials.get_access_token,
-                                 additional_claims={'aud': context.service_url})
-    else:
-      future = self._pool.submit(self._credentials.get_access_token)
-    future.add_done_callback(lambda x: self._get_token_callback(callback, x))
-
-  def _get_token_callback(self, callback, future):
-    try:
-      access_token = future.result().access_token
-    except Exception as e:
-      _sign_request(callback, None, e)
-    else:
-      _sign_request(callback, access_token, None)
-
-  def __del__(self):
-    self._pool.shutdown(wait=False)
+    """Metadata wrapper for GoogleCredentials from the oauth2client library."""
+
+    def __init__(self, credentials):
+        self._credentials = credentials
+        self._pool = futures.ThreadPoolExecutor(max_workers=1)
+
+        # Hack to determine if these are JWT creds and we need to pass
+        # additional_claims when getting a token
+        if 'additional_claims' in inspect.getargspec(
+                credentials.get_access_token).args:
+            self._is_jwt = True
+        else:
+            self._is_jwt = False
+
+    def __call__(self, context, callback):
+        # MetadataPlugins cannot block (see grpc.beta.interfaces.py)
+        if self._is_jwt:
+            future = self._pool.submit(
+                self._credentials.get_access_token,
+                additional_claims={'aud': context.service_url})
+        else:
+            future = self._pool.submit(self._credentials.get_access_token)
+        future.add_done_callback(
+            lambda x: self._get_token_callback(callback, x))
+
+    def _get_token_callback(self, callback, future):
+        try:
+            access_token = future.result().access_token
+        except Exception as e:
+            _sign_request(callback, None, e)
+        else:
+            _sign_request(callback, access_token, None)
+
+    def __del__(self):
+        self._pool.shutdown(wait=False)
 
 
 class AccessTokenCallCredentials(grpc.AuthMetadataPlugin):
-  """Metadata wrapper for raw access token credentials."""
+    """Metadata wrapper for raw access token credentials."""
 
-  def __init__(self, access_token):
-    self._access_token = access_token
+    def __init__(self, access_token):
+        self._access_token = access_token
 
-  def __call__(self, context, callback):
-    _sign_request(callback, self._access_token, None)
+    def __call__(self, context, callback):
+        _sign_request(callback, self._access_token, None)