use strict;
use warnings;
use MyClass::A ();

my $s = MyClass::A->new();
$s->serve();

##</code><code>##

use strict;
use warnings

package MyClass::A;

sub new {
  my $pkg = shift;
  my $self = {};
  return bless $self, $pkg;
}

sub serve {
  my $self = shift;
  # .. do whatevs
}

1;