Function secret_refs 

pub fn secret_refs(
    raw: &Value,
) -> impl Iterator<Item = (Option<&str>, AuthoredPath)> + '_

Every {"secret": …} reference, as the literal name (None when the name is computed) and where the reference sits. Lazy, so a caller that only asks whether one exists (via next()) stops at the first.

The walk goes into the argument too, since a computed name may itself read a secret.