code: func (t *translator) T(key interface{}, params ...string) (string, error) {
  
  	trans, ok := t.translations[key]
  	if !ok {
  		return unknownTranslation, ErrUnknowTranslation
  	}
  
  	b := make([]byte, 0, 64)
  
  	var start, end, count int
  
  	for i := 0; i < len(trans.indexes); i++ {
  		end = trans.indexes[i]
  		b = append(b, trans.text[start:end]...)
  		b = append(b, params[count]...)
  		i++
  		start = trans.indexes[i]
  		count++
  	}
  
  	b = append(b, trans.text[start:]...)
  
  	return string(b), nil
  }
docs: // T creates the translation for the locale given the 'key' and params passed in