-test_dump({2 => 1, _a => 1}, "{2:1,\"_a\":1}", {pretty=>0});
-test_dump({2 => 1, _a => 1}, "{2:1}", {pretty=>0, skip_keys_qr => qr/^_/});
+test_dump({2 => 1, _a => 1}, "{\"2\":1,\"_a\":1}", {pretty=>0});
+test_dump({2 => 1, _a => 1}, "{\"2\":1}", {pretty=>0, skip_keys_qr => qr/^_/});