code: def test_round_30min(self):
      # round
      dt = Timestamp("20130104 12:32:00")
      result = dt.round("30Min")
      expected = Timestamp("20130104 12:30:00")
      assert result == expected
  
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 4 for calling the TestTimestampRound obj's underlying member method code with example usage: obj.test_round_30min() without return types