{"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"lhs_hir_id:"}]}
                lhs_hir_id: lhs_expr.hir_id,
            ObligationCauseCode::BinOp {
                rhs_hir_id: opt_rhs_expr.map(|expr| expr.hir_id),