Function resolve_part_pin 

pub fn resolve_part_pin(
    ports: &BTreeMap<String, PortRecord>,
    part: &str,
    group: Option<&str>,
    pin: &str,
) -> Result<String, String>

The part-local address that pin pin names among a part’s own connection points, as its parts-library entry carries them (crate::PartsLibraryEntry::ports). part only names the part in a refusal; group narrows it as resolve_component_pin’s does.