sub init {
  ## initialize stuff
  $cache=new GNS::Cache;
}
sub uninit {
  undef $cache;
}

##</code><code>##

GNS::Node::init();
my $x=new GNS::Node;
my $y=new GNS::Node;
## blah blah blah
## do some stuff
GNS::Node::uninit();