my $customer1 = DB::Helper->new('id customer 1', 'customer', 'euro', '...', '...', '...');
my $customer2 = DB::Helper->new('id customer 2', 'customer', 'euro', '...', '...', '...');
my $customer3 = DB::Helper->new('id customer 3', 'customer', 'euro', '...', '...', '...');
my $customer4 = DB::Helper->new('id customer 1', 'customer', 'euro', '...', '...', '...');