add override for new bigtable rpc

Author: scotthart

google/cloud/bigtable/internal/bigtable_channel_refresh.cc

@@ -71,6 +71,13 @@ BigtableChannelRefresh::ReadModifyWriteRow(
   return child_->ReadModifyWriteRow(client_context, options, request);
 }
 
+StatusOr<google::bigtable::v2::PrepareQueryResponse>
+BigtableChannelRefresh::PrepareQuery(
+    grpc::ClientContext& client_context, Options const& options,
+    google::bigtable::v2::PrepareQueryRequest const& request) {
+  return child_->PrepareQuery(client_context, options, request);
+}
+
 std::unique_ptr<google::cloud::internal::StreamingReadRpc<
     google::bigtable::v2::ExecuteQueryResponse>>
 BigtableChannelRefresh::ExecuteQuery(

google/cloud/bigtable/internal/bigtable_channel_refresh.h

@@ -77,6 +77,10 @@ class BigtableChannelRefresh : public BigtableStub {
       grpc::ClientContext& client_context, Options const& options,
       google::bigtable::v2::ReadModifyWriteRowRequest const& request) override;
 
+  StatusOr<google::bigtable::v2::PrepareQueryResponse> PrepareQuery(
+      grpc::ClientContext& client, Options const& options,
+      google::bigtable::v2::PrepareQueryRequest const& request) override;
+
   std::unique_ptr<google::cloud::internal::StreamingReadRpc<
       google::bigtable::v2::ExecuteQueryResponse>>
   ExecuteQuery(

google/cloud/bigtable/testing/mock_bigtable_stub.h

@@ -62,6 +62,11 @@ class MockBigtableStub : public bigtable_internal::BigtableStub {
               (grpc::ClientContext&, Options const&,
                google::bigtable::v2::ReadModifyWriteRowRequest const&),
               (override));
+  MOCK_METHOD(StatusOr<google::bigtable::v2::PrepareQueryResponse>,
+              PrepareQuery,
+              (grpc::ClientContext&, Options const&,
+               google::bigtable::v2::PrepareQueryRequest const&),
+              (override));
   MOCK_METHOD(std::unique_ptr<google::cloud::internal::StreamingReadRpc<
                   google::bigtable::v2::ExecuteQueryResponse>>,
               ExecuteQuery,