{"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"type_op_prove_predicate_with_cause(&ocx,"}]}
        type_op_prove_predicate_with_cause(&ocx, key, cause);
        let ocx = ObligationCtxt::new(&infcx);
        let diag = try_extract_error_from_fulfill_cx(