Row headings in flexdashboard

Hi all

I was wondering how I can add row titles to my flexdashboard. For example, above the first set of 4 value boxes it should say "Instrument Class 1". Code is below.

Edit: Sorry formatting is all over the place. Also here on pastebin


title: "Dashboard Example"
output:
flexdashboard::flex_dashboard:
orientation: rows

library(flexdashboard)

Instrument Class 1

Instrument 1

valueBox("Batch A", caption = NULL, icon = NULL, color = "success", href = NULL)

Instrument 2

valueBox("Not in use", caption = NULL, icon = NULL, color = "#7f7f7f", href = NULL)

Instrument 3

valueBox("Batch B", caption = NULL, icon = NULL, color = "success", href = NULL)

Instrument 4

valueBox("Not in use", caption = NULL, icon = NULL, color = "#7f7f7f", href = NULL)

Instrument Class 2

Instrument 5

valueBox("Not in use", caption = NULL, icon = NULL, color = "#7f7f7f", href = NULL)

Instrument 6

valueBox("Batch C", caption = NULL, icon = NULL, color = "success", href = NULL)