code: def _fillna(
      df: pd.DataFrame, value: Any = NAN_REPLACEMENT
  ) -> pd.DataFrame:
      """Fill nan values."""
      return pd.DataFrame(
          {
              name: (_fillna_col(column, value))
              for name, column in df.items()
          }
      )
  
file_path: deepchecks/deepchecks/tabular/checks/train_test_validation/train_test_samples_mix.py
imports: from typing import Any, List
  import pandas
  from pandas.core.dtypes.common import is_integer_dtype
  from deepchecks.core import CheckResult
  from deepchecks.tabular import Context, TrainTestCheck
  from deepchecks.utils.abstracts.train_test_samples_mix import TrainTestSamplesMixAbstract
  from deepchecks.utils.strings import format_percent
  from deepchecks.utils.typing import Hashable
label_desc: Use image node_id 5 for calling a global function with example usage: _fillna(df, value) and returns: pd