void checkNotifications(int expectedNumUpdates, String expectedServiceId, Long expectedExpiresAtMs) {
    assertEquals("Incorrect number of updates", expectedNumUpdates, updatesInitiated.get());
    if (expectedNumUpdates > 0) {
      assertFalse("Received mismatched data in notification system update", mismatchedData.get());
      assertEquals("Unexpected value for service ID", expectedServiceId, receivedUpdateServiceId.get());
      assertEquals("Unexpected value for expiresAtMs", expectedExpiresAtMs, receivedUpdateExpiresAtMs.get());
    }
  }
Checks the notification system updates
@param expectedNumUpdates the number of update events expected
@param expectedServiceId the service id expected in the update events
@param expectedExpiresAtMs the expiry time (ms) expected in the update events
ambry-router/src/test/java/com/github/ambry/router/TtlUpdateManagerTest.java