Function basic 

pub fn basic<'r, 'v, 'p, 'm, 'd, 'a, 's, 'path, D: Copy + Eq, G: Copy + Eq>(
    bound: &'r Bound<'v, 'p, 'm, 'd, 'a, 's, 'path, D, G>,
    counters: Paths<'r, 'm, 'd, 'path>,
    parent: &Reader<'_>,
) -> Result<Basic<'r, 'v, 'p, 'm, 'd, 'a, 's, 'path, D, G>>

Joins the actual root association with ALL original counters. The existing common assembly checks source, selected-root and exact member provenance; only PAdES’s independently prepared root format replaces CAdES B-B fields.