{"ast_node_type":"variable","tokens":[{"end":42,"kind":"keyword","start":0,"text":"let"}]}
            let (trait_args, assoc_args) =
            let parent_len = generics.parent_generics().map_or(0, |g| g.len_self());
                projection_ty.substitution.as_slice(Interner).split_at(parent_len);