class_docstr: DatasetBuilder for robomimic datasets.
code: def _get_metadata(self) -> Dict[Any, Any]:
      return {}
  
imports: import dataclasses
  import enum
  from typing import Any, Dict, List, Mapping
  from etils import epath
  import h5py
  import numpy
  import tensorflow_datasets.public_api
  import tree
label_desc: Use image node_id 3 for calling the RobomimicBuilder obj's underlying member method code with example usage: obj._get_metadata() and returns: dict