src/vs/workbench/contrib/notebook/browser/viewParts/notebookEditorWidgetContextKeys.ts/NotebookEditorContextKeys/_updateForInstalledExtension
class NotebookEditorContextKeys:	private async _updateForInstalledExtension(): Promise<void> {
		if (!this._editor.hasModel()) {
			return;
		}

		const viewType = this._editor.textModel.viewType;
		const kernelExtensionId = KERNEL_EXTENSIONS.get(viewType);
		this._missingKernelExtension.set(
			!!kernelExtensionId && !(await this._extensionService.getExtension(kernelExtensionId)));
	}