public function testAncestorKey()
{
$ds = $this->prophesize(DatastoreClient::class);
$ds->key(Argument::any(), Argument::any())->will(function ($args) {
return new Key('my-awesome-project', ['path' => [['kind' => $args[0], 'name' => $args[1]]]]);
});
$snippet = $this->snippetFromMethod(Key::class, 'ancestorKey');
$snippet->addLocal('key', $this->key);
$snippet->addLocal('datastore', $ds->reveal());
$res = $snippet->invoke();
$this->assertEquals('Dad', $this->key->path()[0]['name']);
}