code: func CreateRegommendItem(key interface{}, data map[interface{}]float64) RegommendItem {
  	return RegommendItem{
  		key:           key,
  		data:          data,
  	}
  }
docs: // CreateRegommendItem returns a newly created RegommendItem.
  // Parameter key is the item's key.
  // Parameter data is the item's value.