private void waitForTracker(String blobId) {
    if (!TestUtils.checkAndSleep(() -> objectTracker.containsKey(blobId), TRACKER_TIMEOUT_MS)) {
      Assert.fail("Tracker not found for " + blobId);
    }
  }
Wait for event tracker to be created for {@code blobId}
@param blobId the ID of the blob
ambry-test-utils/src/main/java/com/github/ambry/server/MockNotificationSystem.java