sub foo {
  my ($self, $caller, @targets) = @_;

  for my $obj ( @targets ) {
    $obj->bar($self, ... );
  }
}

sub bar {
  my ($self, $caller, @args) = @_;

  ...
}

##</code><code>##

  sub handle_event {
    my ($kernel, $heap, $parameter) = @_[KERNEL, HEAP, ARG0];
    ...;
  }