code: function asPath({ ancestors }) {
    const path = [];
  
    for (const { key } of ancestors) {
      if (key != null) {
        if (typeof key === 'number') {
          path.push(`[${key}]`);
        } else {
          path.push(`['${stringify(key).slice(1, -1)}']`);
        }
      }
    }
  
    return path.join('');
  }
docs: Based on `key` in ancestral records, format property path to offending entity.