src/vs/workbench/api/common/extHostExtensionActivator.ts/ExtensionsActivator/getActivatedExtension
class ExtensionsActivator:	public getActivatedExtension(extensionId: ExtensionIdentifier): ActivatedExtension {
		const extensionKey = ExtensionIdentifier.toKey(extensionId);

		const activatedExtension = this._activatedExtensions.get(extensionKey);
		if (!activatedExtension) {
			throw new Error('Extension `' + extensionId.value + '` is not known or not activated');
		}
		return activatedExtension;
	}