diff --git a/spanner/google/cloud/spanner_admin_database_v1/gapic/database_admin_client.py b/spanner/google/cloud/spanner_admin_database_v1/gapic/database_admin_client.py
index d42fe7352bc7..14057c4b231c 100644
--- a/spanner/google/cloud/spanner_admin_database_v1/gapic/database_admin_client.py
+++ b/spanner/google/cloud/spanner_admin_database_v1/gapic/database_admin_client.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Accesses the google.spanner.admin.database.v1 DatabaseAdmin API."""
 
 import functools
@@ -43,6 +44,7 @@
 from google.longrunning import operations_pb2
 from google.protobuf import empty_pb2
 
+
 _GAPIC_LIBRARY_VERSION = pkg_resources.get_distribution("google-cloud-spanner").version
 
 
diff --git a/spanner/google/cloud/spanner_admin_database_v1/gapic/enums.py b/spanner/google/cloud/spanner_admin_database_v1/gapic/enums.py
index 7ccbf87e037e..eab6503a65bc 100644
--- a/spanner/google/cloud/spanner_admin_database_v1/gapic/enums.py
+++ b/spanner/google/cloud/spanner_admin_database_v1/gapic/enums.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Wrappers for protocol buffer enum types."""
 
 import enum
diff --git a/spanner/google/cloud/spanner_admin_database_v1/gapic/transports/database_admin_grpc_transport.py b/spanner/google/cloud/spanner_admin_database_v1/gapic/transports/database_admin_grpc_transport.py
index 133b5ee4f18c..5ff079270022 100644
--- a/spanner/google/cloud/spanner_admin_database_v1/gapic/transports/database_admin_grpc_transport.py
+++ b/spanner/google/cloud/spanner_admin_database_v1/gapic/transports/database_admin_grpc_transport.py
@@ -14,6 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
 import google.api_core.grpc_helpers
 import google.api_core.operations_v1
 
diff --git a/spanner/google/cloud/spanner_admin_instance_v1/gapic/enums.py b/spanner/google/cloud/spanner_admin_instance_v1/gapic/enums.py
index 83325d0cf179..93650fd1f4a8 100644
--- a/spanner/google/cloud/spanner_admin_instance_v1/gapic/enums.py
+++ b/spanner/google/cloud/spanner_admin_instance_v1/gapic/enums.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Wrappers for protocol buffer enum types."""
 
 import enum
diff --git a/spanner/google/cloud/spanner_admin_instance_v1/gapic/instance_admin_client.py b/spanner/google/cloud/spanner_admin_instance_v1/gapic/instance_admin_client.py
index e5bb9b75a8b1..ee1439c1bb36 100644
--- a/spanner/google/cloud/spanner_admin_instance_v1/gapic/instance_admin_client.py
+++ b/spanner/google/cloud/spanner_admin_instance_v1/gapic/instance_admin_client.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Accesses the google.spanner.admin.instance.v1 InstanceAdmin API."""
 
 import functools
@@ -44,6 +45,7 @@
 from google.protobuf import empty_pb2
 from google.protobuf import field_mask_pb2
 
+
 _GAPIC_LIBRARY_VERSION = pkg_resources.get_distribution("google-cloud-spanner").version
 
 
diff --git a/spanner/google/cloud/spanner_admin_instance_v1/gapic/transports/instance_admin_grpc_transport.py b/spanner/google/cloud/spanner_admin_instance_v1/gapic/transports/instance_admin_grpc_transport.py
index bcc34114db29..8dff15a3cd2e 100644
--- a/spanner/google/cloud/spanner_admin_instance_v1/gapic/transports/instance_admin_grpc_transport.py
+++ b/spanner/google/cloud/spanner_admin_instance_v1/gapic/transports/instance_admin_grpc_transport.py
@@ -14,6 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
 import google.api_core.grpc_helpers
 import google.api_core.operations_v1
 
diff --git a/spanner/google/cloud/spanner_v1/gapic/enums.py b/spanner/google/cloud/spanner_v1/gapic/enums.py
index e876b201f9fc..5f38def2b828 100644
--- a/spanner/google/cloud/spanner_v1/gapic/enums.py
+++ b/spanner/google/cloud/spanner_v1/gapic/enums.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Wrappers for protocol buffer enum types."""
 
 import enum
diff --git a/spanner/google/cloud/spanner_v1/gapic/spanner_client.py b/spanner/google/cloud/spanner_v1/gapic/spanner_client.py
index 8613368c7a81..fcabc35e188b 100644
--- a/spanner/google/cloud/spanner_v1/gapic/spanner_client.py
+++ b/spanner/google/cloud/spanner_v1/gapic/spanner_client.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Accesses the google.spanner.v1 Spanner API."""
 
 import functools
@@ -42,6 +43,7 @@
 from google.protobuf import empty_pb2
 from google.protobuf import struct_pb2
 
+
 _GAPIC_LIBRARY_VERSION = pkg_resources.get_distribution("google-cloud-spanner").version
 
 
diff --git a/spanner/google/cloud/spanner_v1/gapic/transports/spanner_grpc_transport.py b/spanner/google/cloud/spanner_v1/gapic/transports/spanner_grpc_transport.py
index 85d8a4a9f247..a0a128fce16f 100644
--- a/spanner/google/cloud/spanner_v1/gapic/transports/spanner_grpc_transport.py
+++ b/spanner/google/cloud/spanner_v1/gapic/transports/spanner_grpc_transport.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import pkg_resources
-import grpc_gcp
 
 import google.api_core.grpc_helpers
 
diff --git a/spanner/synth.metadata b/spanner/synth.metadata
index 6a702d51cece..a351fe13991a 100644
--- a/spanner/synth.metadata
+++ b/spanner/synth.metadata
@@ -1,19 +1,19 @@
 {
-  "updateTime": "2019-05-09T18:33:02.121279Z",
+  "updateTime": "2019-05-21T12:31:40.316493Z",
   "sources": [
     {
       "generator": {
         "name": "artman",
-        "version": "0.19.0",
-        "dockerImage": "googleapis/artman@sha256:d3df563538225ac6caac45d8ad86499500211d1bcb2536955a6dbda15e1b368e"
+        "version": "0.20.0",
+        "dockerImage": "googleapis/artman@sha256:3246adac900f4bdbd62920e80de2e5877380e44036b3feae13667ec255ebf5ec"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "f86c9531dc49d41267e2117ece1ea29840f15ce3",
-        "internalRef": "247457584"
+        "sha": "32a10f69e2c9ce15bba13ab1ff928bacebb25160",
+        "internalRef": "249058354"
       }
     },
     {
diff --git a/spanner/tests/unit/gapic/v1/test_database_admin_client_v1.py b/spanner/tests/unit/gapic/v1/test_database_admin_client_v1.py
index ed6bc9ea1668..166e823b371b 100644
--- a/spanner/tests/unit/gapic/v1/test_database_admin_client_v1.py
+++ b/spanner/tests/unit/gapic/v1/test_database_admin_client_v1.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Unit tests."""
 
 import mock
diff --git a/spanner/tests/unit/gapic/v1/test_instance_admin_client_v1.py b/spanner/tests/unit/gapic/v1/test_instance_admin_client_v1.py
index c1388cbb3799..60f63938f976 100644
--- a/spanner/tests/unit/gapic/v1/test_instance_admin_client_v1.py
+++ b/spanner/tests/unit/gapic/v1/test_instance_admin_client_v1.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Unit tests."""
 
 import mock
diff --git a/spanner/tests/unit/gapic/v1/test_spanner_client_v1.py b/spanner/tests/unit/gapic/v1/test_spanner_client_v1.py
index a5f05ba3a194..40a8de679f57 100644
--- a/spanner/tests/unit/gapic/v1/test_spanner_client_v1.py
+++ b/spanner/tests/unit/gapic/v1/test_spanner_client_v1.py
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 """Unit tests."""
 
 import mock
