Function parse_library_ref 

pub fn parse_library_ref(s: &str) -> Result<LibraryRef, XmlError>

Splits a reference string into (library, name).

Accepted forms:

1. "library::name" — qualified.
2. "name" — unqualified (library empty).

Errors

• XmlError::UnresolvedReference — empty string, or "::name", or "library::", or more than two :: segments.