# E3 (extra-spec): leading + rejected. "+1" is non-canonical → ineligible.
# Eligible key: "0" only. Impl test: getList("items") returns ["b"].
# Lightbend behaviour: accepts "+1" as 1; result ["b","a"]. Documented in expected/.../na10a-plus-sign.divergence.md.
items = {"+1":"a","0":"b"}