public function testDistance()
{
$data_a = ['id' => str_repeat('FF', N / 8)];
$node_a = KademliaTestFactory::constructNode($data_a);
$zeros = Kademlia\Node::hexId2bin(str_repeat('00', N / 8));
$this->assertEqual($node_a->distanceTo($node_a), $zeros);
$data_b = ['id' => str_repeat('FF', N / 8)];
$data_b['id'][2 * N / 8 - 1] = 'E';
$node_b = KademliaTestFactory::constructNode($data_b);
$one = Kademlia\Node::hexid2bin(str_repeat('0', 2 * N / 8 - 1) . '1');
$this->assertEqual($node_a->distanceTo($node_b), $one);
}