src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts/BackLayerWebView/getNotebookBaseUri
class BackLayerWebView:	private getNotebookBaseUri() {
		if (this.documentUri.scheme === Schemas.untitled || this.documentUri.scheme === Schemas.vscodeInteractive) {
			const folder = this.workspaceContextService.getWorkspaceFolder(this.documentUri);
			if (folder) {
				return folder.uri;
			}

			const folders = this.workspaceContextService.getWorkspace().folders;
			if (folders.length) {
				return folders[0].uri;
			}
		}

		return dirname(this.documentUri);
	}