Why Satellite API activationkey.listActivationKeys returns empty array?

Issue

• Satellite API activationkey.listActivationKeys returns an empty array.

• Sample perl script which is returning the empty array,

#!/usr/bin/perl
use Frontier::Client;

my $HOST = 'example.satellite.com';
my $user = 'test';
my $pass = 'test';

my $client = new Frontier::Client(url => "http://$HOST/rpc/api");
my $session = $client->call('auth.login',$user, $pass);

my $ActivationKeys = $client->call('activationkey.listActivationKeys', $session);
$size = scalar(@ActivationKeys);
print "size : $size\n";
foreach my $ActivationKey (@ActivationKeys) {
   print $ActivationKey->{'key'}."\n";
   print $ActivationKey->{'description'}."\n";
}
$client->call('auth.logout', $session);