code: def test_to_csv_mixed(self):
      def create_cols(name):
          return [f"{name}{i:03d}" for i in range(5)]
  
      df_float = DataFrame(
          np.random.default_rng(2).standard_normal((100, 5)),
          dtype="float64",
          columns=create_cols("float"),
      )
      df_int = DataFrame(
          np.random.default_rng(2)
          .standard_normal((100, 5))
          .astype("int64"),
          dtype="int64",
          columns=create_cols("int"),
      )
      df_bool = DataFrame(
          True, index=df_float.index, columns=create_cols("bool")
      )
      df_object = DataFrame(
          "foo", index=df_float.index, columns=create_cols("object")
      )
      df_dt = DataFrame(
          Timestamp("20010101").as_unit("ns"),
          index=df_float.index,
          columns=create_cols("date"),
      )
  
      # add in some nans
      df_float.iloc[30:50, 1:3] = np.nan
      df_dt.iloc[30:50, 1:3] = np.nan
  
      df = pd.concat(
          [df_float, df_int, df_bool, df_object, df_dt], axis=1
      )
  
      # dtype
      dtypes = {}
      for n, dtype in [
          ("float", np.float64),
          ("int", np.int64),
          ("bool", np.bool_),
          ("object", object),
      ]:
          for c in create_cols(n):
              dtypes[c] = dtype
  
      with tm.ensure_clean() as filename:
          df.to_csv(filename)
          rs = read_csv(
              filename,
              index_col=0,
              dtype=dtypes,
              parse_dates=create_cols("date"),
          )
          tm.assert_frame_equal(rs, df)
  
imports: import csv
  from io import StringIO
  import os
  import numpy
  import pytest
  from pandas.errors import ParserError
  import pandas
  from pandas import DataFrame, Index, MultiIndex, NaT, Series, Timestamp, date_range, period_range, read_csv, to_datetime
  import pandas._testing
  import pandas.core.common
  from pandas.io.common import get_handle
label_desc: Use image node_id 27 for calling the TestDataFrameToCSV obj's underlying member method code with example usage: obj.test_to_csv_mixed() and returns: unknown