my @browsers = ('firefox', 'chrome', 'internet explorer');
my @random_array = shuffle(@browsers);
for my $b1_idx (0 .. $#random_array - 1) {
  my $b1 = $screen{ $browsers[$b1_idx] };
  for my $b2_idx ($b1_idx .. $#browsers) {
      my $b2 = $screen{ $browsers[$b2_idx] };
   
      unless ($b1->compare($b2)) {
          my $diff_file = $b1->difference($b2);
   
          print '#The images are not the same; see' . $diff_file .' for details'."\n";
          qx{ $diff_file };
      }

  }
}

##</code><code>##

my @browsers = ('firefox', 'chrome', 'internet explorer');