my $printsub = sub {
  my $node = shift;
  if (defined $node) {
    my $node_data = $node->{data};
    if (defined $node_data and ref $node_data eq 'HASH') {
      print "node_data dir_name holds $node_data->{dir_name}\n";
      print "node_data dir_vep holds $node_data->{dir_vep}\n";
    }
  } 
  return 0;
}