package Parent {
   sub legacy_method {
      my ($self, @args) = @_;
      return $self->current_method(@args);
   }
   sub current_method {
      return 1;
   }
}

package Child {
   use base 'Parent';
   sub current_method {
      return 2;
   }
}

Child->legacy_method;  # returns 2

##</code><code>##

sub legacy_method {
  my $next = $_[0]->can('current_method');
  goto $next;
}