use warnings;
use strict;
use Data::Dumper;

my %hash = (first => '1', second => '2');

print "Original: " . Dumper (\%hash);

my %newHash = %{inAndOut (%hash)};

print "\nnew hash: " . Dumper (\%newHash);


sub inAndOut {
  my (%hash) = @_;
  
  print "\nin sub: " . Dumper (\%hash);
  return {%hash};
}