code: def test_fillna_dtype_conversion_equiv_replace(self, val):
      df = DataFrame({"A": [1, np.nan], "B": [1.0, 2.0]})
      expected = df.replace(np.nan, val)
      result = df.fillna(val)
      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 19 for calling the TestFillNA obj's underlying member method code with example usage: obj.test_fillna_dtype_conversion_equiv_replace(val) without return types