code: def test_round_mixed_type(self):
      # GH#11885
      df = DataFrame(
          {
              "col1": [1.1, 2.2, 3.3, 4.4],
              "col2": ["1", "a", "c", "f"],
              "col3": date_range("20111111", periods=4),
          }
      )
      round_0 = DataFrame(
          {
              "col1": [1.0, 2.0, 3.0, 4.0],
              "col2": ["1", "a", "c", "f"],
              "col3": date_range("20111111", periods=4),
          }
      )
      tm.assert_frame_equal(df.round(), round_0)
      tm.assert_frame_equal(df.round(1), df)
      tm.assert_frame_equal(df.round({"col1": 1}), df)
      tm.assert_frame_equal(df.round({"col1": 0}), round_0)
      tm.assert_frame_equal(df.round({"col1": 0, "col2": 1}), round_0)
      tm.assert_frame_equal(df.round({"col3": 1}), df)
  
file_path: pandas/pandas/tests/frame/methods/test_round.py
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Series, date_range
  import pandas._testing
label_desc: Use image node_id 4 for calling the TestDataFrameRound obj's underlying member method code with example usage: obj.test_round_mixed_type() without return types