An R Markdown file with cells with different types of package imports

```{r}
# Use of library
library(ggplot2)
```

```{r}
# Use of require
require(dplyr)
```

```{r}
# Use of function exported by the package
lubridate::now()
```

```{r}
# Use of function not exported by the package
digest:::sha1()
```
