package MyPackage;

use base qw(MyPackage::Base);

__PACKAGE__->add_column('name');
__PACKAGE__->add_column('address');

1;

##</code><code>##

my $class_body = sub {
    package MyPackage;

    use base qw(MyPackage::Base);

    sub initialize_class {
        my ($this) = @_;

        $this->add_column('name');
        $this->add_column('address');
    }

    1;
}
__PACKAGE__->build_class($class_body);