private static String toFanOutStoreKey(TaskName taskName) {
    Preconditions.checkArgument(taskName != null, "TaskName should be defined");
    Preconditions.checkArgument(StringUtils.isNotBlank(taskName.getTaskName()), "TaskName should not be blank");

    return taskName.getTaskName();
  }
Deletes all fanned out {@link Startpoint}s
samza-core/src/main/java/org/apache/samza/startpoint/StartpointManager.java