code: def validate_key(obj, key, object_label=None):
      if key not in obj:
          missing_key_error(key, object_label)
  
file_path: snips-nlu/snips_nlu/common/dataset_utils.py
imports: from snips_nlu.constants import INTENTS, UTTERANCES, DATA, SLOT_NAME, ENTITY
  from snips_nlu.exceptions import DatasetFormatError
label_desc: Use image node_id 4 for calling a global function with example usage: validate_key(obj, key, object_label) without return types