code: def test_empty_frame_groupby_dtypes_consistency(self, d):
      # GH 20888
      group_keys = ["a", "b", "c"]
      df = DataFrame({"a": [1], "b": [2], "c": [3], "d": [d]})
  
      g = df[df.a == 2].groupby(group_keys)
      result = g.first().index
      expected = MultiIndex(
          levels=[[1], [2], [3]],
          codes=[[], [], []],
          names=["a", "b", "c"],
      )
  
      tm.assert_index_equal(result, expected)
  
imports: import datetime
  import numpy
  import pytest
  import pandas
  from pandas import DataFrame, MultiIndex, Series
  import pandas._testing
label_desc: Use image node_id 13 for calling the TestMultiLevel obj's underlying member method code with example usage: obj.test_empty_frame_groupby_dtypes_consistency(d) without return types