Indetifying groups in a treemap

[ManuelSpinola]

Is there a way to display the name of the gropu in a treemap. I can see the different colors, but I cannot see to which group belong, in this example, to which continent.

```r
library(dplyr)
data(gapminder, package = "gapminder")

gapminder_2007 <- gapminder::gapminder %>%
  filter(year == max(year)) %>%
  mutate(pop_mm = round(pop / 1e6))

dout <- data_to_hierarchical(gapminder_2007, c(continent, country), pop_mm)
```

```{r}
hchart(dout, type = "treemap")
```