{"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"(lhs_expr,"}]}
        (lhs_expr, lhs_ty): (&'tcx hir::Expr<'tcx>, Ty<'tcx>),
        &self,
        opt_rhs: Option<(&'tcx hir::Expr<'tcx>, Ty<'tcx>)>,