diff --git a/absl/log/log_sink.cc b/absl/log/log_sink.cc
new file mode 100644
index 0000000..01d7ca8
--- /dev/null
+++ b/absl/log/log_sink.cc
@@ -0,0 +1,23 @@
+// Copyright 2022 The Abseil Authors
+//
+// 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
+//
+//     https://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.
+
+#include "absl/log/log_sink.h"
+
+#include "absl/base/config.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+void LogSink::KeyFunction() const {}
+ABSL_NAMESPACE_END
+}  // namespace absl