$mu->record($your message here);

##</code><code>##

$mu->record->($msg here);
##</code><code>##

#! perl -sl

use strict;
use warnings;
use Memory::Usage;
use Data::Dump qw(dump);

my $mu = Memory::Usage->new();
$mu->record('start =>');
open FH, '<', $ARGV[0] or die "file not found";

my $line = 0;
my %hash
;
while( <FH> ) {
    $hash{ $line } = undef;
    $line++;
}
close FH;
$mu->record('end   =>');
print dump($mu->state());