public void addNode(final INaviViewNode node){
  Preconditions.checkNotNull(node,"Error: node argument can not be null");
  Preconditions.checkArgument(!m_nodeCache.contains(node),"Error: node can not be added more then once");
  m_nodeCache.add(node);
  final int index=m_nodeCache.indexOf(node);
  fireTableRowsInserted(index,index);
}

public void addNode ( final INaviViewNode node ) { Preconditions . checkNotNull ( node , "Error: node argument can not be null" ) ; Preconditions . checkArgument ( ! m_nodeCache . contains ( node ) , "Error: node can not be added more then once" ) ; m_nodeCache . add ( node ) ; final int index = m_nodeCache . indexOf ( node ) ; fireTableRowsInserted ( index , index ) ; }
this function is invoked from external if a node is added to the model .
