$ cat graph.t

#!/usr/bin/env perl
use strict;
use warnings;
use Graph;
use Test::More qw( no_plan );

my @vertices = qw( Jolt Lord Tornado );

my $g = Graph->new(vertices => [ @vertices ]);
ok(defined $g, "Constructor returned defined value");
isa_ok($g, 'Graph');
for my $v (@vertices) {
    ok($g->has_vertex($v), "vertex $v");
}

my @edges = (
    [ 'Tornado'     => 'Jolt' ],
    [ 'Tornado'     => 'Lord' ],
);
for my $e (@edges) {
    ok($g->add_edge(@{$e}), sprintf("Add edge %-12s -> %s", @{$e}));
}