adds back the page_size proto

Author: chalmerlowe

tests/fragments/test_pagination_page_size.proto

@@ -0,0 +1,36 @@
+// Copyright (C) 2021  Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// 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.
+
+syntax = "proto3";
+
+package google.fragment;
+
+import "google/api/client.proto";
+import "google/protobuf/wrappers.proto";
+
+service PageSizeDatasetService {
+  option (google.api.default_host) = "my.example.com";
+  rpc ListPageSizeDataset(ListPageSizeDatasetRequest) returns (ListPageSizeDatasetResponse) {
+  }
+}
+
+message ListPageSizeDatasetRequest {
+  int32 page_size = 2;
+  string page_token = 3;
+}
+
+message ListPageSizeDatasetResponse {
+  string next_page_token = 3;
+  repeated string datasets = 4;
+}