code: function createStringifyStream(opts) {
      assert.object(opts, 'opts');
      assert.ok(Array.isArray(opts.body) || typeof opts.body === 'object',
          'opts.body must be an array or object');
  
      return stringifyStreamFactory(opts.body, null, null, true);
  }
docs: create a JSON.stringify readable stream.
  @public
  @param {Object} opts an options object
  @param {Object} opts.body the JS object to JSON.stringify
  @function createStringifyStream
  @return {Stream}