src/vs/workbench/services/extensions/browser/extensionUrlHandler.ts/ExtensionUrlHandler/registerExtensionHandler
class ExtensionUrlHandler:	registerExtensionHandler(extensionId: ExtensionIdentifier, handler: IURLHandler): void {
		this.extensionHandlers.set(ExtensionIdentifier.toKey(extensionId), handler);

		const uris = this.uriBuffer.get(ExtensionIdentifier.toKey(extensionId)) || [];

		for (const { uri } of uris) {
			this.handleURLByExtension(extensionId, handler, uri);
		}

		this.uriBuffer.delete(ExtensionIdentifier.toKey(extensionId));
	}