extensions/markdown-language-features/src/commands/showPreview.ts/ShowPreviewToSideCommand/execute
class ShowPreviewToSideCommand:	public execute(uri?: vscode.Uri, previewSettings?: DynamicPreviewSettings) {
		showPreview(this._webviewManager, this._telemetryReporter, uri, {
			sideBySide: true,
			locked: previewSettings && previewSettings.locked
		});
	}