docs: function serializeAllDates(obj) {
  
          // if it is a date, then return serialized version
          if (_.isDate(obj)) {
              return serializeDate(obj);
          }
  
          // if array or object, loop over it
          if (_.isArray(obj) || _.isObject(obj)) {
              _.forEach(obj, function (item, key) {
                  obj[key] = serializeAllDates(item);
              });
          }
  
          return obj;
      }