public function testKey()
{
$snippet = $this->snippetFromMethod(DatastoreClient::class, 'key');
$snippet->addLocal('datastore', $this->client);
$res = $snippet->invoke('key');
$this->assertInstanceOf(Key::class, $res->returnVal());
$pathElement = $res->returnVal()->keyObject()['path'][0];
$this->assertEquals(['kind' => 'Person', 'name' => 'Bob'], $pathElement);
}