class_docstr: A learning rate decay policy, where the effective learning rate
  follows a polynomial decay, to be zero by the max_iteration.
  Calculation: base_lr (1 - iter/max_iteration) ^ (power)
  
  
  :param power: coeffient of decay, refer to calculation formula
  :param max_iteration: max iteration when lr becomes zero
  
  >>> poly = Poly(0.5, 2)
  creating: createPoly
code: def get_scheduler(self) -> "optimizer.Poly":
      return self.scheduler
  
imports: from abc import ABC, abstractmethod
  from typing import List, Optional, TYPE_CHECKING
label_desc: Use image node_id 2 for calling the Poly obj's underlying member method code with example usage: obj.get_scheduler() and returns: self