ResourceNode(final Node parent,final File file){
  super(parent);
  checkNotNull(file,"file");
  checkArgument(file.exists(),"File '" + file + "' does not exist.");
  this.file=file;
}

ResourceNode ( final Node parent , final File file ) { super ( parent ) ; checkNotNull ( file , "file" ) ; checkArgument ( file . exists ( ) , "File '" + file + "' does not exist." ) ; this . file = file ; }
creates a new node instance representing a file resource .
