@nodes = (
    { id => 17, size => 300, keys => 2, cmp => 'keys' },
    { id => 14, size => 104, keys => 9, cmp => 'size' },
    { id => 31, size => 2045, keys => 43, cmp => 'keys' },
    { id => 28, size => 6, keys => 0, cmp => 'id' },
  );