{"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"CandidateSource::BuiltinImpl(BuiltinImplSource::TraitUpcasting(idx)),"}]}
                    CandidateSource::BuiltinImpl(BuiltinImplSource::TraitUpcasting(idx)),
                    goal,
                    a_data,