package my_test_package;

# Create a package global.
my $ME = undef;

# Return the required reference.
sub new {
  # If $ME has been set do not bother doing all the init again.
  return $ME if defined $ME;

  my $class = shift;
  my $self = {};

  # A lot of long-winded initialization.

  bless $self, $class;
  $ME = $self;
  return $self;
}
1;