class_docstr: This class just allows us to implement ``Registrable`` for Pytorch :class:`LRSchedulers`.
code: def step_batch(self, batch_num_total):
      if batch_num_total is not None:
          if hasattr(self.lr_scheduler, "step_batch"):
              self.lr_scheduler.step_batch(batch_num_total)
          return
  
imports: from __future__ import absolute_import
  import torch.optim.lr_scheduler
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.params import Params
  from allennlp.common.registrable import Registrable
label_desc: Use image node_id 3 for calling the LearningRateScheduler obj's underlying member method code with example usage: obj.step_batch(batch_num_total) without return types