Iam in the process of understanding this script. I just now started leaning perl language, But confusion with Data::Dumper and print Dumper modules.Please explain this code. 
#!/usr/local/bin/perl -w
use strict;
use Data::Dumper;
use Net::FTP;
use lib '/export/home/pvuser/lib';
use Eirteic;
#
#
my $er = Eirteic->start;

#
# Initialise Library
#
if( @ARGV > 0 ) { # Arg we testing or for real ?
    $er->{test} = 1;
    $er->{debug} = 1;
}
$er->log( "Getting Customer Groups" );
$er->getCustomerGroups();
if( $er->{debug} > 1 ) {
    print "Usage:\n";
    print Dumper %usage;
    print "Latency:\n";
    print Dumper %latency;
    print "Jitter:\n";
    print Dumper %jitter;
    print "Site:\n";
    print Dumper %site;
}

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In reply to Use of Data::Dumper by Parimala@123

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