extensions/markdown-language-features/src/preview/previewManager.ts/PreviewStore/_resolvePreviewColumn
class PreviewStore:	private _resolvePreviewColumn(previewSettings: DynamicPreviewSettings): vscode.ViewColumn | undefined {
		if (previewSettings.previewColumn === vscode.ViewColumn.Active) {
			return vscode.window.tabGroups.activeTabGroup.viewColumn;
		}

		if (previewSettings.previewColumn === vscode.ViewColumn.Beside) {
			return vscode.window.tabGroups.activeTabGroup.viewColumn + 1;
		}

		return previewSettings.previewColumn;
	}