{
   package Tester;
   use Tie::Hash qw();
   our @ISA = 'Tie::StdHash';
   sub DELETE {
      my $self = shift;
      print("DELETE @_\n");
      $self->SUPER::DELETE(@_)
   }
}

{
   tie my %hash, 'Tester';
   %hash = (
      a => 1,
      b => 2,
      c => 3,
      d => 4,
   );
   delete @hash{qw( b c )};
   print(join(' ', keys %hash), "\n");
}