sub new {
    return bless {}, shift;
}
sub add {
    shift; # throw away object/class; not needed
    my ($x, $y) = @_;
    return $x + $y;
}

##</code><code>##

my $res = Module->add(1, 2);

# or

my $obj = Module->new;
my $res = $obj->add(1, 2);

# or even

my $mod = 'Module';

my $res = $mod->add(1, 2);

##</code><code>##

my $mod = 'My::Long::Module::Name';

{ # test 1
    my $obj = $mod->new;
}
{ # test 2
    my $obj = $mod->new;
}

# etc