-is_deeply(add('list'), { list => 1 }, 'add list');
-is_deeply(add(1, 'list'), { list => 1 }, 'add const, list');
-is_deeply(add({ }, 'list'), { list => 1 }, 'add empty-ref, list');
-is_deeply(add({ 1 => 1 }, 'list'), { list => 1 }, 'add ref, list');
-is_deeply(add({ 1 => 1 }, 1), { 1 => 2 }, 'add ref, prev-const');
+is_deeply(add('list'), { list => 1 }, 'add list');
+is_deeply(add(1, 'list'), { 1 => 1, list => 1 }, 'add const, list');
+is_deeply(add({ }, 'list'), { list => 1 }, 'add empty-ref, list');
+is_deeply(add({ 1 => 1 }, 'list'), { 1 => 1, list => 1 }, 'add ref, list');
+is_deeply(add({ 1 => 1 }, 1), { 1 => 2 }, 'add ref, prev-const');