class_docstr: Wrapper around features dict for accessing keys and values for slicing.
code: def has_key(self, key: str):
      for d in self._features_dicts:
          if key in d and d[key] is not None:
              return True
      if (
          self._default_features_dict
          and key in self._default_features_dict
          and self._default_features_dict[key] is not None
      ):
          return True
      return False
  
file_path: model-analysis/tensorflow_model_analysis/slicer/slice_accessor.py
imports: from typing import Iterable, List, Optional, Union
  import numpy
  import pyarrow
  import tensorflow
  from tensorflow_model_analysis.api import types
label_desc: Use image node_id 2 for calling the SliceAccessor obj's underlying member method code with example usage: obj.has_key(key) and returns: False, True, True