Function foreign_class 

pub fn foreign_class(ns: &str, local: &str) -> &'static ClassDef

The class of an object no class table knows — a SKOS concept, a PROV agent, a DCAT catalogue — named by its namespace and local name. One leaked ClassDef per distinct class, kept for the process like intern’s keys. Its qualified name is the class IRI, which no family’s by_type keys use.