feat: add support for asynchronous long running operations (#724)

* feat: implement `OperationsRestAsyncTransport` to support long running operations (#700)

* feat: Add OperationsRestAsyncTransport to support long running operations

* update TODO comment

* update TODO comment

* address feedback

* address feedback

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* fix mypy and lint issues

* minor fix

* add no cover

* fix no cover tag

* link coverage issue

* silence coverage issue

* fix statement name error

* address PR feedback

* address PR feedback

* address PR comments

---------

Co-authored-by: ohmayr <omairnaveed@ymail.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

* feat: implement async client for LROs (#707)

* feat: implement `AbstractOperationsAsyncClient` to support long running operations

* remove coverage guards

* address presubmit failures

* fix coverage for cancel operation

* tests cleanup

* fix incorrect tests

* file bugs

* add auth import

* address PR comments

* address PR comments

* fix unit tests and address more comments

* disable retry parameter

* add retry parameter

* address PR comments

---------

Co-authored-by: ohmayr <omairnaveed@ymail.com>
Co-authored-by: ohmayr <omairn@google.com>

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Anthonios Partheniou <partheniou@google.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: 3 people

google/api_core/client_info.py

@@ -57,7 +57,8 @@ class ClientInfo(object):
         user_agent (Optional[str]): Prefix to the user agent header. This is
             used to supply information such as application name or partner tool.
             Recommended format: ``application-or-tool-ID/major.minor.version``.
-        rest_version (Optional[str]): The requests library version.
+        rest_version (Optional[str]): A string with labeled versions of the
+            dependencies used for REST transport.
     """
 
     def __init__(

google/api_core/gapic_v1/client_info.py

@@ -45,6 +45,8 @@ class ClientInfo(client_info.ClientInfo):
         user_agent (Optional[str]): Prefix to the user agent header. This is
             used to supply information such as application name or partner tool.
             Recommended format: ``application-or-tool-ID/major.minor.version``.
+        rest_version (Optional[str]): A string with labeled versions of the
+            dependencies used for REST transport.
     """
 
     def to_grpc_metadata(self):

google/api_core/operations_v1/__init__.py

@@ -14,9 +14,7 @@
 
 """Package for interacting with the google.longrunning.operations meta-API."""
 
-from google.api_core.operations_v1.abstract_operations_client import (
-    AbstractOperationsClient,
-)
+from google.api_core.operations_v1.abstract_operations_client import AbstractOperationsClient
 from google.api_core.operations_v1.operations_async_client import OperationsAsyncClient
 from google.api_core.operations_v1.operations_client import OperationsClient
 from google.api_core.operations_v1.transports.rest import OperationsRestTransport
@@ -25,5 +23,18 @@
     "AbstractOperationsClient",
     "OperationsAsyncClient",
     "OperationsClient",
-    "OperationsRestTransport",
+    "OperationsRestTransport"
 ]
+
+try:
+    from google.api_core.operations_v1.transports.rest_asyncio import (
+        AsyncOperationsRestTransport,
+    )
+    from google.api_core.operations_v1.operations_rest_client_async import AsyncOperationsRestClient
+
+    __all__ += ["AsyncOperationsRestClient", "AsyncOperationsRestTransport"]
+except ImportError:
+    # This import requires the `async_rest` extra.
+    # Don't raise an exception if `AsyncOperationsRestTransport` cannot be imported
+    # as other transports are still available.
+    pass