code: def next_batch(self) -> Dict[str, np.ndarray]:
      raise NotImplementedError()
  
file_path: ludwig/ludwig/data/batcher/base.py
imports: from abc import ABC, abstractmethod
  from typing import Dict
  import numpy
label_desc: Use image node_id 1 for calling the Batcher obj's underlying member method code with example usage: obj.next_batch() without return types