extensions/markdown-language-features/src/preview/topmostLineMonitor.ts/TopmostLineMonitor/getPreviousStaticTextEditorLineByUri
class TopmostLineMonitor:	public getPreviousStaticTextEditorLineByUri(resource: vscode.Uri): number | undefined {
		const state = this.previousStaticEditorInfo.get(resource.toString());
		return state?.line;
	}