code: function getProductsDetailsStream (ids) {
    var stream = JSONStream.stringify(false);
    Promise.each(ids, function (id) {
      return this.getProductDetails(id).then(function (detail) {
        if (detail) {
          stream.write(detail);
        }
        return Promise.resolve();
      });
    }.bind(this));
    return stream;
  }
docs: [getProductsDetailsStream description]
  
  @param  {[type]} ids [description]
  @return {[type]}     [description]