Method describe

src/ExtMsg.actor.cpp:1362–1362

	Future<Void> update(Reference<IReadWriteContext> document) override { return replacementActor(this, document); }

	std::string describe() override { return "ReplaceWith(" + replaceWith.toString() + ")"; }

	ACTOR static Future<Void> replacementActor(ExtReplaceUpdate* self, Reference<IReadWriteContext> document) {
		state Standalone<StringRef> keyEncodedId = wait(document->getKeyEncodedId());