/**
* @covers ::getIdentityKey
*/
public function testGetIdentityKey()
{
$city = new City();
$this->assertNull($city->getIdentityKey());
$city = new City(['id' => 10]);
$this->assertNull($city->getIdentityKey());
$city = new City(['id' => 10], State::SAVED);
$this->assertEquals(10, $city->getIdentityKey());
}