code: def test_ceil(self, unit):
      dt = Timestamp("20130101 09:10:11").as_unit(unit)
      result = dt.ceil("D")
      expected = Timestamp("20130102")
      assert result == expected
      assert result._creso == dt._creso
  
imports: from hypothesis import given, strategies
  import numpy
  import pytest
  import pytz
  from pandas._libs import lib
  from pandas._libs.tslibs import NaT, OutOfBoundsDatetime, Timedelta, Timestamp, iNaT, to_offset
  from pandas._libs.tslibs.dtypes import NpyDatetimeUnit
  from pandas._libs.tslibs.period import INVALID_FREQ_ERR_MSG
  import pandas._testing
label_desc: Use image node_id 10 for calling the TestTimestampRound obj's underlying member method code with example usage: obj.test_ceil(unit) without return types