@hash1_guts = (  # scalar(%hash1) is 2/8
   undef,
   [ $node1 ],
   undef,
   undef,
   undef,
   undef,
   [ $node2, $node3, $node4, $node5, $node6, $node7 ],
   undef,
);

@hash2_guts = (  # scalar(%hash2) is 6/8
   [ $node1 ],
   [ $node2 ],
   [ $node3 ],
   [ $node4, $node5 ],
   [ $node6 ],
   undef,
   undef,
   [ $node7 ],
);