1 files changed, 62 insertions, 61 deletions
diff --git a/src/python/grpcio/grpc/_plugin_wrapping.py b/src/python/grpcio/grpc/_plugin_wrapping.py
index 7cb5218c22..bb9a42f3ff 100644
--- a/src/python/grpcio/grpc/_plugin_wrapping.py
+++ b/src/python/grpcio/grpc/_plugin_wrapping.py
@@ -36,82 +36,82 @@ from grpc._cython import cygrpc
 
 
 class AuthMetadataContext(
-    collections.namedtuple(
-        'AuthMetadataContext', ('service_url', 'method_name',)),
-    grpc.AuthMetadataContext):
-  pass
+        collections.namedtuple('AuthMetadataContext', (
+            'service_url',
+            'method_name',)), grpc.AuthMetadataContext):
+    pass
 
 
 class AuthMetadataPluginCallback(grpc.AuthMetadataContext):
 
-  def __init__(self, callback):
-    self._callback = callback
+    def __init__(self, callback):
+        self._callback = callback
 
-  def __call__(self, metadata, error):
-    self._callback(metadata, error)
+    def __call__(self, metadata, error):
+        self._callback(metadata, error)
 
 
 class _WrappedCygrpcCallback(object):
 
-  def __init__(self, cygrpc_callback):
-    self.is_called = False
-    self.error = None
-    self.is_called_lock = threading.Lock()
-    self.cygrpc_callback = cygrpc_callback
-
-  def _invoke_failure(self, error):
-    # TODO(atash) translate different Exception superclasses into different
-    # status codes.
-    self.cygrpc_callback(
-        _common.EMPTY_METADATA, cygrpc.StatusCode.internal,
-        _common.encode(str(error)))
-
-  def _invoke_success(self, metadata):
-    try:
-      cygrpc_metadata = _common.cygrpc_metadata(metadata)
-    except Exception as error:
-      self._invoke_failure(error)
-      return
-    self.cygrpc_callback(cygrpc_metadata, cygrpc.StatusCode.ok, b'')
-
-  def __call__(self, metadata, error):
-    with self.is_called_lock:
-      if self.is_called:
-        raise RuntimeError('callback should only ever be invoked once')
-      if self.error:
-        self._invoke_failure(self.error)
-        return
-      self.is_called = True
-    if error is None:
-      self._invoke_success(metadata)
-    else:
-      self._invoke_failure(error)
-
-  def notify_failure(self, error):
-    with self.is_called_lock:
-      if not self.is_called:
-        self.error = error
+    def __init__(self, cygrpc_callback):
+        self.is_called = False
+        self.error = None
+        self.is_called_lock = threading.Lock()
+        self.cygrpc_callback = cygrpc_callback
+
+    def _invoke_failure(self, error):
+        # TODO(atash) translate different Exception superclasses into different
+        # status codes.
+        self.cygrpc_callback(_common.EMPTY_METADATA, cygrpc.StatusCode.internal,
+                             _common.encode(str(error)))
+
+    def _invoke_success(self, metadata):
+        try:
+            cygrpc_metadata = _common.cygrpc_metadata(metadata)
+        except Exception as error:
+            self._invoke_failure(error)
+            return
+        self.cygrpc_callback(cygrpc_metadata, cygrpc.StatusCode.ok, b'')
+
+    def __call__(self, metadata, error):
+        with self.is_called_lock:
+            if self.is_called:
+                raise RuntimeError('callback should only ever be invoked once')
+            if self.error:
+                self._invoke_failure(self.error)
+                return
+            self.is_called = True
+        if error is None:
+            self._invoke_success(metadata)
+        else:
+            self._invoke_failure(error)
+
+    def notify_failure(self, error):
+        with self.is_called_lock:
+            if not self.is_called:
+                self.error = error
 
 
 class _WrappedPlugin(object):
 
-  def __init__(self, plugin):
-    self.plugin = plugin
+    def __init__(self, plugin):
+        self.plugin = plugin
 
-  def __call__(self, context, cygrpc_callback):
-    wrapped_cygrpc_callback = _WrappedCygrpcCallback(cygrpc_callback)
-    wrapped_context = AuthMetadataContext(
-        _common.decode(context.service_url), _common.decode(context.method_name))
-    try:
-      self.plugin(
-          wrapped_context, AuthMetadataPluginCallback(wrapped_cygrpc_callback))
-    except Exception as error:
-      wrapped_cygrpc_callback.notify_failure(error)
-      raise
+    def __call__(self, context, cygrpc_callback):
+        wrapped_cygrpc_callback = _WrappedCygrpcCallback(cygrpc_callback)
+        wrapped_context = AuthMetadataContext(
+            _common.decode(context.service_url),
+            _common.decode(context.method_name))
+        try:
+            self.plugin(wrapped_context,
+                        AuthMetadataPluginCallback(wrapped_cygrpc_callback))
+        except Exception as error:
+            wrapped_cygrpc_callback.notify_failure(error)
+            raise
 
 
 def call_credentials_metadata_plugin(plugin, name):
-  """
+    """
   Args:
     plugin: A callable accepting a grpc.AuthMetadataContext
       object and a callback (itself accepting a list of metadata key/value
@@ -119,5 +119,6 @@ def call_credentials_metadata_plugin(plugin, name):
       called, but need not be called in plugin's invocation.
       plugin's invocation must be non-blocking.
   """
-  return cygrpc.call_credentials_metadata_plugin(
-      cygrpc.CredentialsMetadataPlugin(_WrappedPlugin(plugin), _common.encode(name)))
+    return cygrpc.call_credentials_metadata_plugin(
+        cygrpc.CredentialsMetadataPlugin(
+            _WrappedPlugin(plugin), _common.encode(name)))