code: def afterOptimizerStep(
      self, retrievedPosIndexes, retrievedNegIndexes=None
  ):
      torch.cuda.synchronize()
      cupy.cuda.Device().synchronize()
  
      reshapedRetrieval = self._getReshapedRetrieval(
          retrievedPosIndexes, retrievedNegIndexes
      )
  
      for idx, optVar in enumerate(self.optVarList):
          self.CUPYcorpi[idx][reshapedRetrieval] = cupy.fromDlpack(
              to_dlpack(
                  self.given_optimizer.state_dict()["state"][
                      self.optimizerKey
                  ][optVar]
              )
          )
  
imports: import numpy
  import cupy
  import torch
  import os
  from torch.utils.dlpack import to_dlpack
  from torch.utils.dlpack import from_dlpack
label_desc: Use image node_id 4 for calling the OptimizerFactory obj's underlying member method code with example usage: obj.afterOptimizerStep(retrievedPosIndexes, retrievedNegIndexes) without return types