package Example::Module;
use strict;

# note, we don't actually have to use the reference that we 
# bless. we just need it for its unique reference id.
sub new { bless {}, shift }

{
  my %value;
  my %counter;

  sub accumulate {
    my $self = shift;
    for (@_) {
      $value{ $self } += $_;
      $counter{ $self }++;
    }
  }

  sub printvalue {
    my $self = shift;
    printf "%s has value %2d from %2d iterations.\n",
           $self, $value{$self}, $counter{$self};
  }

  # prevent memory leaks.
  DESTROY {
    my $self = shift;
    delete $value{$self};
    delete $counter{$self};
  }
}

1;