code: def _empty_or_constant(data_block):
      return (
          data_block.shape[1] == 0 or max(data_block.std(axis=0)) == 0
      )
  
imports: from abc import ABC, abstractmethod
  import numpy
  from collections import defaultdict
  from sklearn.ensemble import BaseEnsemble
  from sklearn.ensemble._forest import _generate_unsampled_indices, _generate_sample_indices
  from .local_stumps import make_stumps, tree_feature_transform
label_desc: Use image node_id 3 for calling a global function with example usage: _empty_or_constant(data_block) and returns: unknown