src/vs/workbench/services/extensions/common/extensionHostManager.ts/ExtensionHostManager/start
class ExtensionHostManager:	public async start(enabledExtensionIds: ExtensionIdentifier[]): Promise<void> {
		const proxy = await this._proxy;
		if (!proxy) {
			return;
		}
		this._extensionHost.extensions.keepOnly(enabledExtensionIds);
		return proxy.startExtensionHost(enabledExtensionIds);
	}