use 5.014;
use warnings;

use XML::Simple qw( :strict );   # Taken from OP.
use File::Slurper qw( read_binary );

my $xml = read_binary($ARGV[0]);

# Make sure we know which parser is being used.
local $XML::Simple::PREFERRED_PARSER = 'XML::Parser';

# Taken from OP.
my $doc = XMLin($xml, ForceArray => 1,KeyAttr => [ ]);

say sprintf "%vX", $doc;