Update _OperationsFuture usage.

speech/google/cloud/speech/_gax.py

@@ -106,7 +106,7 @@ def async_recognize(self, sample, language_code=None,
         api = self._gapic_api
         operation_future = api.async_recognize(config=config, audio=audio)
 
-        return Operation.from_pb(operation_future._operation, self)
+        return Operation.from_pb(operation_future.last_operation_data(), self)
 
     def streaming_recognize(self, sample, language_code=None,
                             max_alternatives=None, profanity_filter=None,

speech/unit_tests/test_client.py

@@ -725,13 +725,16 @@ def __init__(self, response=None, channel=None):
         self._channel = channel
 
     def async_recognize(self, config, audio):
+        from google.gapic.longrunning.operations_client import OperationsClient
         from google.gax import _OperationFuture
         from google.longrunning.operations_pb2 import Operation
+        from google.cloud.proto.speech.v1beta1.cloud_speech_pb2 import (
+            AsyncRecognizeResponse)
 
         self.config = config
         self.audio = audio
-        operation_future = mock.Mock(spec=_OperationFuture)
-        operation_future._operation = Operation()
+        operation_future = _OperationFuture(Operation(), OperationsClient(),
+                                            AsyncRecognizeResponse, {})
         return operation_future
 
     def sync_recognize(self, config, audio):