@Override
      protected Component getHeader() {
        if (0 == myTree.getY()) {
          return null; // separator is not needed without scrolling
        }
        if (myHeader == null) {
          myHeader = new JLabel();
          myHeader.setForeground(UIUtil.getTreeForeground());
          myHeader.setIconTextGap(JBUIScale.scale(ICON_GAP));
          myHeader.setBorder(JBUI.Borders.empty(2, 10 + getLeftMargin(0), 0, 0));
        }
        myHeader.setFont(myTree.getFont());
        myHeader.setIcon(getIcon(null, false));
        int height = myHeader.getPreferredSize().height;
        String group = findGroupNameAt(0, height + 3);
        if (group == null || !group.equals(findGroupNameAt(0, 0))) {
          return null; // do not show separator over another group
        }
        myHeader.setText(group);
        return myHeader;
      }
@Override
      protected Component getHeader()