package GlobalHash;

use vars qw(@EXPORT @EXPORT_OK $VERSION $REVISION $AUTOLOAD @ISA);
use Exporter;
...

use Tie::RefHash;
use Class::StrongSingleton;
use base qw(Class::StrongSingleton Tie::RefHash::Nestable );

sub TIEHASH {
  my $proto = shift;
  my $class = ref($proto) || $proto;
  my $self  = {@_};
  $self = Tie::RefHash::Nestable->TIEHASH($self, $class);
  # initialize it as a singleton
  $self->_init_StrongSingleton();

  $self->{'START'}  = scalar localtime;

  return $self;
}