#!/usr/bin/perl --
use strict;
use warnings;
use WWW::Mechanize 1.86;
... # your other modules
Main( @ARGV );
exit( 0 );
sub Main {
    my $user =
    ... 
    GetSaveOMI( $user, $password , 'events.xml' );
}
sub GetSaveOMI {
    my( $user, $password, $outfile ) = @_;
    my $omi_url =  ...;
    my $ua = WWW::Mechanize->new( ... );
    $ua->get( $omi_url , ':content_file' => $outfile ); ## regular LWP usage
    return $ua;
}