Fix various mind-numbing typos

src/python/grpcio/grpc/_channel.py

@@ -25,7 +25,7 @@ from grpc._cython import cygrpc
 from grpc.framework.foundation import callable_util
 
 _LOGGER = logging.getLogger(__name__)
-_LOGGER.addHandler(logging.NullHandler)
+_LOGGER.addHandler(logging.NullHandler())
 
 _USER_AGENT = 'grpc-python/{}'.format(_grpcio_metadata.__version__)
 

src/python/grpcio/grpc/framework/foundation/stream_util.py

@@ -20,7 +20,7 @@ from grpc.framework.foundation import stream
 
 _NO_VALUE = object()
 _LOGGER = logging.getLogger(__name__)
-_LOGGER.addHandler(NullHandler())
+_LOGGER.addHandler(logging.NullHandler())
 
 
 class TransformingConsumer(stream.Consumer):

src/python/grpcio_tests/tests/unit/_api_test.py

@@ -14,6 +14,7 @@
 """Test of gRPC Python's application-layer API."""
 
 import unittest
+import logging
 
 import six
 

src/python/grpcio_tests/tests/unit/_auth_context_test.py

@@ -15,6 +15,7 @@
 
 import pickle
 import unittest
+import logging
 
 import grpc
 from grpc import _channel

src/python/grpcio_tests/tests/unit/_auth_test.py

@@ -16,6 +16,7 @@
 import collections
 import threading
 import unittest
+import logging
 
 from grpc import _auth