code: def test_ninteraction_datetime_series():
      # When a pandas datetime is converted Numpy datetime, the two
      # no longer compare as equal! This test ensures that case is
      # not happening
      lst = ["2020-01-01", "2020-01-02", "2020-01-03"]
      data1 = pd.DataFrame(
          {
              "x": list("abcaabbcc"),
              "date_list": lst * 3,
          }
      )
      data2 = pd.DataFrame(
          {
              "x": list("abcaabbcc"),
              "date_list": pd.to_datetime(lst * 3),
          }
      )
  
      assert ninteraction(data1) == ninteraction(data2)
  
file_path: plotnine/tests/test_utils.py
imports: import itertools
  import random
  import string
  import warnings
  import numpy
  import pandas
  from plotnine._utils import _margins, add_margins, join_keys, match, ninteraction, pivot_apply, remove_missing, uniquecols
  from plotnine.data import mtcars
label_desc: Use image node_id 4 for calling a global function with example usage: test_ninteraction_datetime_series() without return types