code: private void doSelect(int startPosition, int endPosition, boolean anchorIsStart) {
          doUpdate(() -> {
              delegateSelection.selectRange(startPosition, endPosition);
              internalStartedByAnchor.setValue(anchorIsStart);
  
              delegateCaret.moveTo(anchorIsStart ? endPosition : startPosition);
          });
      }
docs: /* ********************************************************************** *
  *
  Private methods                                                        *
  *
  **********************************************************************