package Singleton;
use strict;
use vars qw($singleton);

sub new {
  $singleton and return $singleton;
  my $class = shift;
  my $self = {};
  $self->{value} = 0;
  $singleton = $self;
  bless $self, $class;
}
sub getValue {
  my $self = shift;
  return $self->{value};
}
sub setValue {
  my $self = shift;
  $self->{value} = shift;
}
1;