code: def test_to_xarray_index_types(
      self, index_flat, df, using_infer_string
  ):
      index = index_flat
      # MultiIndex is tested in test_to_xarray_with_multiindex
      if len(index) == 0:
          pytest.skip("Test doesn't make sense for empty index")
  
      from xarray import Dataset
  
      df.index = index[:4]
      df.index.name = "foo"
      df.columns.name = "bar"
      result = df.to_xarray()
      assert result.dims["foo"] == 4
      assert len(result.coords) == 1
      assert len(result.data_vars) == 8
      tm.assert_almost_equal(list(result.coords.keys()), ["foo"])
      assert isinstance(result, Dataset)
  
      # idempotency
      # datetimes w/tz are preserved
      # column names are lost
      expected = df.copy()
      expected["f"] = expected["f"].astype(
          object if not using_infer_string else "string[pyarrow_numpy]"
      )
      expected.columns.name = None
      tm.assert_frame_equal(result.to_dataframe(), expected)
  
file_path: pandas/pandas/tests/generic/test_to_xarray.py
imports: import numpy
  import pytest
  from pandas import Categorical, DataFrame, MultiIndex, Series, date_range
  import pandas._testing
label_desc: Use image node_id 2 for calling the TestDataFrameToXArray obj's underlying member method code with example usage: obj.test_to_xarray_index_types(index_flat, df, using_infer_string) without return types