docs: public void startInterval(int firstIndex) {
          Object value = getCurrentValue();
          if (isOpen)
              throw new IllegalStateException("PathDetailsBuilder is already in an open state with value: " + currentDetail.getValue()
                      + " trying to open a new one with value: " + value);
  
          currentDetail = new PathDetail(value);
          currentDetail.setFirst(firstIndex);
          isOpen = true;
      }