sub addexit {
  my ($self, $exit, $direction) = @_;
  $self->{'_exits'}->{$direction} = $exit;
}

sub addhiddenexit {
  my ($self, $exit, $direction) = @_;
  $self->{'_hiddenexists'}->{$direction} = $exit;
}

sub showexits {
  my ($self) = @_;
  my $message = join "\n", 'The following exits are available:',
    map { '    $_\n' } sort keys %{ $self->{'_exits'} };
  return $message;
}

sub exit {
  my ($self, $direction) = @_;
  if ( exists($self->{'_hiddenexits'}->{$direction}) ) {
    return $self->{'_hiddenexits'}->{$direction};
  }
  if ( exists($self->{'_exits'}->{$direction}) ) {
    return $self->{'_exits'}->{$direction};
  }
  return undef;
}