class_docstr: A trigger specifies a timespot or several timespots during training,
  and a corresponding action will be taken when the timespot(s) is reached.
  SeveralIteration is a trigger that triggers an action every "n"
  iterations.
  Could be used as trigger in setvalidation and setcheckpoint in Optimizer,
  and also in TrainSummary.set_summary_trigger.
  
  
  >>> serveralIteration = SeveralIteration(2)
code: def __init__(self, interval: int) -> None:
      from bigdl.dllib.optim.optimizer import SeveralIteration
  
      self.trigger = SeveralIteration(interval)
  
file_path: BigDL/python/orca/src/bigdl/orca/learn/trigger.py
imports: from abc import ABC, abstractmethod
  from typing import TYPE_CHECKING
  from typing import Union, Optional
label_desc: Use image node_id 1 to create a new SeveralIteration object from inherited base classes: Trigger with example: obj = SeveralIteration(interval)