Function new_sorter_lexicographic 

pub fn new_sorter_lexicographic(sorters: Vec<BoxedSorterFn>) -> impl Sorter

Create a new sorter that will run multiple sorters. When the nth sorter returns Ordering::Equal, the next sorter is called. It stops as soon as a sorter return Ordering::Greater or Ordering::Less.

This is an implementation of a lexicographic order as defined for cartesian products (learn more).