src/vs/workbench/services/extensions/common/extensionsRegistry.ts/ExtensionMessageCollector/constructor
class ExtensionMessageCollector:	constructor(
		messageHandler: (msg: IMessage) => void,
		extension: IExtensionDescription,
		extensionPointId: string
	) {
		this._messageHandler = messageHandler;
		this._extension = extension;
		this._extensionPointId = extensionPointId;
	}