package plugin;
our @ISA;

sub SAVE {
  print join(',',@ISA)."\n";
  print "SAVE von plugin\n";
}

sub set_isa
{
  my $self=shift;
  my $name=shift;
  @ISA=($name);
}
1;

package klasse;
our @ISA;

sub new { return bless {}, shift; }

sub SAVE { print "SAVE von klasse\n"; }

sub LOAD { print "LOAD von klasse\n"; }

sub use_plugin
{
  my $self=shift;
  my $name=shift;
  bless($self,$name);
  $self->set_isa(__PACKAGE__);
}
1;

my $klasse=klasse->new();
$klasse->use_plugin('plugin');
$klasse->SAVE; # <= das SAVE aus plugin
$klasse->LOAD; # <= das LOAD aus klasse