private function assert($key, $expectedTimestamp, $isEqual = true)
{
// Assert the timestamp
$timestamp = $this->getTimestamp($key);
if ($isEqual) {
// Set timestamp via options or using should be equal
$this->assertEquals($expectedTimestamp, $timestamp);
} else {
// Inserted timestamp (server or local) should be > expected
$this->assertGreaterThan($expectedTimestamp, $timestamp);
}
}