use strict;
use warnings;
use Data::Dumper qw();
use Data::Dump::Streamer qw();

my %switch_param;
my $switch_optional;

$switch_optional->{foo} = 'bar';

my @optional;

for (1 .. 3) {
    @optional = (@optional, $switch_optional);
}

$switch_param{"optional"} = [@optional];

Data::Dump::Streamer::Dump \%switch_param;
print "\n\n";
print Data::Dumper::Dumper (\%switch_param);

##</code><code>##

$HASH1 = { optional => [
           { foo => 'bar' },
           'V: $HASH1->{optional}[0]',
           'V: $HASH1->{optional}[0]'
         ] };
$HASH1->{optional}[1] = $HASH1->{optional}[0];
$HASH1->{optional}[2] = $HASH1->{optional}[0];


$VAR1 = {
          'optional' => [
                          {
                            'foo' => 'bar'
                          },
                          $VAR1->{'optional'}[0],
                          $VAR1->{'optional'}[0]
                        ]
        };