Function reverse_modsum 

pub fn reverse_modsum<'a>(
    spec: &ModSumBuilder<u64>,
    chk_bytes: &[(&'a [u8], Vec<u8>)],
    verbosity: u64,
    extended_search: bool,
) -> impl Iterator<Item = Result<ModSum<u64>, CheckReverserError>> + use<'a>

Find the parameters of a modsum algorithm.

spec contains the known parameters of the algorithm (by setting the corresponding values in the builder). chk_bytes are pairs of files and their checksums. verbosity makes the function output what it is doing

The width parameter of the builder has to be set.