code: def test_nunique_dropna(dropna):
      # GH37566
      ser = pd.Series(["yes", "yes", pd.NA, np.nan, None, pd.NaT])
      res = ser.nunique(dropna)
      assert res == 1 if dropna else 5
  
file_path: pandas/pandas/tests/base/test_unique.py
imports: import numpy
  import pytest
  from pandas._config import using_pyarrow_string_dtype
  import pandas
  import pandas._testing
  from pandas.tests.base.common import allow_na_ops
label_desc: Use image node_id 6 for calling a global function with example usage: test_nunique_dropna(dropna) without return types