public Tree getTree() throws TreeNotFoundException
public Tree getTree()
  public Tree getTree() throws TreeNotFoundException  {    if ((this.tree == null) && (this.treeId != null)        && (this.getSignet() != null))    {      try      {        this.tree        	= (TreeImpl)(this.getSignet().getTree(this.treeId));      }      catch (ObjectNotFoundException onfe)      {        throw new TreeNotFoundException(onfe);      }    }    return this.tree;  }