mergeExtensionFields 1155 third_party/protobuf/java/src/main/java/com/google/protobuf/GeneratedMessage.java     protected final void mergeExtensionFields(final ExtendableMessage other) {
mergeExtensionFields  463 third_party/protobuf/java/src/main/java/com/google/protobuf/GeneratedMessageLite.java     protected final void mergeExtensionFields(final MessageType other) {