code: def test_fillna_columns(self):
      arr = np.random.default_rng(2).standard_normal((10, 10))
      arr[:, ::2] = np.nan
      df = DataFrame(arr)
  
      msg = "DataFrame.fillna with 'method' is deprecated"
      with tm.assert_produces_warning(FutureWarning, match=msg):
          result = df.fillna(method="ffill", axis=1)
      with tm.assert_produces_warning(FutureWarning, match=msg):
          expected = df.T.fillna(method="pad").T
      tm.assert_frame_equal(result, expected)
  
      df.insert(6, "foo", 5)
      with tm.assert_produces_warning(FutureWarning, match=msg):
          result = df.fillna(method="ffill", axis=1)
      with tm.assert_produces_warning(FutureWarning, match=msg):
          expected = df.astype(float).fillna(method="ffill", axis=1)
      tm.assert_frame_equal(result, expected)
  
imports: import numpy
  import pytest
  from pandas._config import using_pyarrow_string_dtype
  from pandas import Categorical, DataFrame, DatetimeIndex, NaT, PeriodIndex, Series, TimedeltaIndex, Timestamp, date_range, to_datetime
  import pandas._testing
  from pandas.tests.frame.common import _check_mixed_float
label_desc: Use image node_id 31 for calling the TestFillNA obj's underlying member method code with example usage: obj.test_fillna_columns() without return types