code: func (t *translator) R(key interface{}, num1 float64, digits1 uint64, num2 float64, digits2 uint64, param1, param2 string) (string, error) {
  
  	tarr, ok := t.rangeTanslations[key]
  	if !ok {
  		return unknownTranslation, ErrUnknowTranslation
  	}
  
  	rule := t.RangePluralRule(num1, digits1, num2, digits2)
  
  	trans := tarr[rule]
  
  	b := make([]byte, 0, 64)
  	b = append(b, trans.text[:trans.indexes[0]]...)
  	b = append(b, param1...)
  	b = append(b, trans.text[trans.indexes[1]:trans.indexes[2]]...)
  	b = append(b, param2...)
  	b = append(b, trans.text[trans.indexes[3]:]...)
  
  	return string(b), nil
  }
docs: // R creates the range translation for the locale given the 'key', 'num1', 'digit1', 'num2' and 'digit2' arguments
  // and 'param1' and 'param2' passed in