code: def _incomplete_cases(df):
      nas = df.isna().sum(axis="columns")
      return nas[nas > 0].index
  
imports: from copy import copy, deepcopy
  import abc
  import inspect
  import importlib
  import itertools
  from collections.abc import Mapping
  import pandas
  from decorator import decorator
  from sklearn_evaluation.exceptions import DataSelectorError
  from sklearn_evaluation.util import map_parameters_in_fn_call
  from sklearn_evaluation.table import Table
label_desc: Use image node_id 9 for calling a global function with example usage: _incomplete_cases(df) and returns: nas