Function gfautil::variants::detect_variants_in_sub_paths

pub fn detect_variants_in_sub_paths(
    variant_config: &VariantConfig, 
    path_data: &PathData, 
    ref_path_names: Option<&FnvHashSet<BString>>, 
    path_indices: &FnvHashMap<u64, FnvHashMap<usize, usize>>, 
    from: u64, 
    to: u64
) -> Option<FnvHashMap<BString, FnvHashMap<VariantKey, FnvHashSet<Variant>>>>