sub findPathsAll {
		  my ($graph,$start,$end) = @_;

		  my $findPaths_sub;
		  $findPaths_sub = sub {
		    my( $seen, $start, $end ) = @_;

		    return [[$end]] if $start eq $end;

		    $seen->{ $start } = 1;
		    my @paths;
		    for my $node ( @{ $graph->{ $start } } ) {
		      my %seen = %{$seen};
		      next if exists $seen{ $node };
		      push @paths, [ $start, @$_ ]
		          for @{ $findPaths_sub->( \%seen, $node, $end ) };
		    }
		    return \@paths;
		  };

		  my @all;
		  push @all,[@$_]  for @{ $findPaths_sub->( {}, $start, $end ) };
		  return @all;
		}