code: def _zeros_like(nest, dtype=None):
      """Generate a nested NumPy array according to spec."""
      return tree.map_structure(
          lambda x: np.zeros(x.shape, dtype or x.dtype), nest
      )
  
file_path: acme/acme/wrappers/concatenate_observations.py
imports: from typing import Sequence, Optional
  from acme import types
  from acme.wrappers import base
  import dm_env
  import numpy
  import tree
label_desc: Use image node_id 2 for calling a global function with example usage: _zeros_like(nest, dtype) and returns: tree