code: public void setOpen(boolean open, boolean fireEvents) {
  
          if (m_open == open) {
              return;
          }
          m_open = open;
          executeOpen(fireEvents);
          CmsDomUtil.resizeAncestor(getParent());
      }
docs: Opens or closes this tree item (i.e. shows or hides its descendants).<p>
  
  @param open if <code>true</code>, open the tree item, else close it
  @param fireEvents true if the open/close events should be fired