\name{str.comb_mat}
 \alias{str.comb_mat}
 \title{
 str method
 }
 \description{
 str method
 }
 \usage{
 \method{str}{comb_mat}(object, ...)
 }
 \arguments{
 
   \item{object}{A combination matrix returned by \code{\link{make_comb_mat}}.}
   \item{...}{Other arguments.}
 
 }
 \examples{
 # There is no example
 NULL

 }