将flexdashboard与多个页面不同类型的vertical_layout结合起来

我创建了一个具有多个页面的 Flexdashboard 文档。我希望在第一页上vetical_layout: fill但在第二页我想要那个vertical_layout: scroll。我的文档是这样开始的：

---
title: "DASHBOARD"
output:
  flexdashboard::flex_dashboard:
    orientation: columns
    logo: logo.png
    vertical_layout: fill
---

我怎样才能看到第二页vertical_layout: scroll?

您可以覆盖全局vertical_layout单个 (H2) 列上的值。

---
title: "Changing Vertical Layout"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
---

```{r setup, include=FALSE}
library(flexdashboard)
library(ggplot2)
```

Page 1
================================

Column {data-width=650}
-----------------------------------------------------------------------

### Panel A
```{r}
qplot(cars$speed)
qplot(cars$dist)
```

Column {data-width=350}
-----------------------------------------------------------------------

### Panel B
```{r}
qplot(cars$speed)
```

### Panel C
```{r}
qplot(cars$dist)
```

Page 2
================================

Column { vertical_layout: scroll}
-----------------------------------------------------------------------

### Panel A 
```{r}
qplot(cars$speed)
qplot(cars$dist)
```

```{r}
qplot(cars$speed)
qplot(cars$dist)
```

```{r}
qplot(cars$speed)
qplot(cars$dist)
```

Here's a similar example of overriding the global values. (But in this case http://rmarkdown.rstudio.com/flexdashboard/layouts.html#multiple_pages, they're changing the orientation at the page (H1) level).