code: public ActivityCodeValue addValue(Integer uniqueID, String name, String description)
     {
        ActivityCodeValue value = new ActivityCodeValue(this, uniqueID, name, description);
        m_values.add(value);
        return value;
     }
docs: Add a value to this activity code.
  
  @param uniqueID value unique ID
  @param name value name
  @param description value description
  @return ActivityCodeValue instance