Make implicit Optional type hints in Quantum Engine PEP 484 compliant (…

…quantumlib#6640)

* implicit optional type hints PEP 484 compliant

* rm type ignore

* add type ignore back

* mypy

cirq-google/cirq_google/cloud/quantum_v1alpha1/services/quantum_engine_service/async_client.py

@@ -34,7 +34,7 @@
 from google.api_core import gapic_v1
 from google.api_core import retry as retries
 from google.auth import credentials as ga_credentials
-from google.oauth2 import service_account  # type: ignore
+from google.oauth2 import service_account
 
 try:
     OptionalRetry = Union[retries.Retry, gapic_v1.method._MethodDefault]
@@ -172,7 +172,7 @@ def transport(self) -> QuantumEngineServiceTransport:
     def __init__(
         self,
         *,
-        credentials: ga_credentials.Credentials = None,
+        credentials: Optional[ga_credentials.Credentials] = None,
         transport: Union[str, QuantumEngineServiceTransport] = "grpc_asyncio",
         client_options: Optional[ClientOptions] = None,
         client_info: gapic_v1.client_info.ClientInfo = DEFAULT_CLIENT_INFO,

cirq-google/cirq_google/cloud/quantum_v1alpha1/services/quantum_engine_service/client.py

@@ -27,7 +27,7 @@
 from google.auth.transport import mtls
 from google.auth.transport.grpc import SslCredentials
 from google.auth.exceptions import MutualTLSChannelError
-from google.oauth2 import service_account  # type: ignore
+from google.oauth2 import service_account
 
 try:
     OptionalRetry = Union[retries.Retry, gapic_v1.method._MethodDefault]

cirq-google/cirq_google/cloud/quantum_v1alpha1/services/quantum_engine_service/transports/base.py

@@ -23,7 +23,7 @@
 from google.api_core import gapic_v1
 from google.api_core import retry as retries
 from google.auth import credentials as ga_credentials
-from google.oauth2 import service_account  # type: ignore
+from google.oauth2 import service_account
 
 from cirq_google.cloud.quantum_v1alpha1.types import engine
 from cirq_google.cloud.quantum_v1alpha1.types import quantum
@@ -48,7 +48,7 @@ def __init__(
         self,
         *,
         host: str = DEFAULT_HOST,
-        credentials: ga_credentials.Credentials = None,
+        credentials: Optional[ga_credentials.Credentials] = None,
         credentials_file: Optional[str] = None,
         scopes: Optional[Sequence[str]] = None,
         quota_project_id: Optional[str] = None,

cirq-google/cirq_google/cloud/quantum_v1alpha1/services/quantum_engine_service/transports/grpc.py

@@ -120,7 +120,7 @@ def __init__(
 
         if channel:
             # Ignore credentials if a channel was passed.
-            credentials = False
+            credentials = None
             # If a channel was explicitly provided, set it.
             self._grpc_channel = channel
             self._ssl_channel_credentials = None

cirq-google/cirq_google/cloud/quantum_v1alpha1/services/quantum_engine_service/transports/grpc_asyncio.py

@@ -51,7 +51,7 @@ class QuantumEngineServiceGrpcAsyncIOTransport(QuantumEngineServiceTransport):
     def create_channel(
         cls,
         host: str = 'quantum.googleapis.com',
-        credentials: ga_credentials.Credentials = None,
+        credentials: Optional[ga_credentials.Credentials] = None,
         credentials_file: Optional[str] = None,
         scopes: Optional[Sequence[str]] = None,
         quota_project_id: Optional[str] = None,
@@ -94,7 +94,7 @@ def __init__(
         self,
         *,
         host: str = 'quantum.googleapis.com',
-        credentials: ga_credentials.Credentials = None,
+        credentials: Optional[ga_credentials.Credentials] = None,
         credentials_file: Optional[str] = None,
         scopes: Optional[Sequence[str]] = None,
         channel: Optional[aio.Channel] = None,
@@ -166,7 +166,7 @@ def __init__(
 
         if channel:
             # Ignore credentials if a channel was passed.
-            credentials = False
+            credentials = None
             # If a channel was explicitly provided, set it.
             self._grpc_channel = channel
             self._ssl_channel_credentials = None