?setindexv lacks example of "cols=<list>" behavior

[MichaelChirico]

In ?setindexv we see:

data.table/man/setkey.Rd

Line 58 in a9cd0bf

\item{cols}{ A character vector of column names. For \code{setindexv}, this can be a \code{list} of character vectors, in which case each element will be applied as an index in turn. }

I would like an example of how exactly that should be specified, but there are none in Examples.

[venom1204]

@MichaelChirico can i work on it .