code: def get_start_end_idx(self) -> Tuple[int, int]:
      start_idx = (
          self.data_parallel_rank
          * self._global_batch_size_on_this_data_parallel_rank
      )
      end_idx = (
          start_idx + self._global_batch_size_on_this_data_parallel_rank
      )
      return start_idx, end_idx
  
imports: import abc
  import warnings
  from typing import Tuple
  import torch
  from nemo.utils.decorators import experimental
label_desc: Use image node_id 1 for calling the MegatronPretrainingBatchSampler obj's underlying member method code with example usage: obj.get_start_end_idx() and returns: start_idx,  end_idx