1package Some::Module;
2use strict;
3use warnings;
4use Exporter 5.57 'import';
5
6our @EXPORT_OK = qw(some_sub);
7
8# This is an example of a subroutine that returns (undef, $msg)
9# to signal failure.
10
11sub some_sub {
12    my ($arg) = @_;
13
14    if ($arg) {
15        return (undef, "Insufficient credit");
16    }
17
18    return (1,2,3);
19}
20
211;
22