# Allows for arbitary number of lines
# (as long as they are sequentially numbered from 1)
sub print_shape {
  my $self=shift;
  my $em='';
  for (my $i=0; $i<scalar(keys %{$self->{shape}}); $i++) {
    $em = 'print $self->{shape}->{line' . ($i+1) . '}."\n"';
    eval($em);
  }
}