Before:
----------------------------------------------------------------------------
do {
  my $a = bless({
    attr1        => "val1",
    circular_ref => 'fix',
    however      => {
                      this => { unwanted => bless({ is => "actually wanted" }, "Unwanted") },
                    },
    internal_ref => 'fix',
    resource     => bless({
                      1    => 2,
                      11   => 12,
                      13   => 14,
                      15   => 16,
                      17   => 18,
                      19   => 20,
                      3    => 4,
                      5    => 6,
                      7    => 8,
                      9    => 10,
                      note => "Defined outside \$hairy_object",
                    }, "Singleton::Resource"),
    Silly        => {
                      complex => { references => "can be mangled", so => "they make more sense." },
                    },
    unwanted     => bless({ thing => "We want to ignore" }, "Unwanted"),
  }, "Hairy::Object");
  $a->{circular_ref} = $a;
  $a->{internal_ref} = $a->{however}{this};
  $a;
}

After:
----------------------------------------------------------------------------
$a = bless( {
   attr1 => "val1",
   circular_ref => 'fix',
   however => # Here, there be dragons
   {
      this => { unwanted => bless({ is => "actually wanted" }, "Unwanted") },
   },
   internal_ref => 'fix',
   resource => $singleton,
   Silly => "references can be mangled so they make more sense.",
}, "Hairy::Object");
$a->{circular_ref} = $a;
$a->{internal_ref} = $a->{however}{this};