code: def test_ffill_mixed_dtypes_without_missing_data(self):
      # GH#14956
      series = Series([datetime(2015, 1, 1, tzinfo=pytz.utc), 1])
      result = series.ffill()
      tm.assert_series_equal(series, result)
  
imports: from datetime import datetime, timedelta, timezone
  import numpy
  import pytest
  import pytz
  from pandas import Categorical, DataFrame, DatetimeIndex, NaT, Period, Series, Timedelta, Timestamp, date_range, isna, timedelta_range
  import pandas._testing
  from pandas.core.arrays import period_array
label_desc: Use image node_id 3 for calling the TestFillnaPad obj's underlying member method code with example usage: obj.test_ffill_mixed_dtypes_without_missing_data() without return types