{"ast_node_type":"variable","tokens":[{"end":98,"kind":"keyword","start":0,"text":"let"}]}
        let candidates = self.assemble_and_evaluate_candidates(goal, AssembleCandidatesFrom::All);
    ) -> Result<(CanonicalResponse<I>, Option<TraitGoalProvenVia>), NoSolution> {
        self.merge_trait_candidates(candidates)