src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts/BackLayerWebView/deleteMarkupPreviews
class BackLayerWebView:	async deleteMarkupPreviews(cellIds: readonly string[]) {
		if (this._disposed) {
			return;
		}

		for (const id of cellIds) {
			if (!this.markupPreviewMapping.has(id)) {
				console.error(`Trying to delete a preview that does not exist: ${id}`);
			}
			this.markupPreviewMapping.delete(id);
		}

		if (cellIds.length) {
			this._sendMessageToWebview({
				type: 'deleteMarkupCell',
				ids: cellIds
			});
		}
	}