const customStringify = function (v) {
  const cache = new Set();
  return JSON.stringify(v, function (key, value) {
    if (typeof value === 'object' && value !== null) {
      if (cache.has(value)) {
        // Circular reference found, discard key
        return;
      }
      // Store value in our set
      cache.add(value);
    }
    return value;
  });
};