{"ast_node_type":"variable","tokens":[{"end":72,"kind":"keyword","start":0,"text":"if"}]}
            if let [trait_segment] = &poly.trait_ref.path.segments[..] {
        |poly: &PolyTraitRef, potential_assoc: &PathSegment, predicate: &WhereEqPredicate| {
                let assoc = pprust::path_to_string(&ast::Path::from_ident(potential_assoc.ident));