lib/utils/stringify.js
function stringify(content) {
  if (typeof content === 'string' && stringifiedRegexp.test(content)) {
    return content;
  }
  return JSON.stringify(content, null, 2);
}
function stringify(content) {
  if (typeof content === 'string' && stringifiedRegexp.test(content)) {
    return content;
  }
  return JSON.stringify(content, null, 2);
}
If already stringified - return original content
@param {Object|Array} content
@return {string}