code: def test_unique(setup, check_ref_counts):
      data1 = pd.Series(np.random.randint(0, 5, size=(20,)))
  
      series = md.Series(data1)
      result = series.unique().execute().fetch()
      expected = data1.unique()
      np.testing.assert_array_equal(result, expected)
  
      series = md.Series(data1, chunk_size=6)
      result = series.unique().execute().fetch()
      expected = data1.unique()
      np.testing.assert_array_equal(result, expected)
  
      data2 = pd.Series(
          [pd.Timestamp("20200101", tz="US/Eastern")] * 5
          + [pd.Timestamp("20200202")]
          + [pd.Timestamp("20020101")] * 9
      )
      series = md.Series(data2)
      result = series.unique().execute().fetch()
      expected = data2.unique()
      np.testing.assert_array_equal(result, expected)
  
      series = md.Series(data2, chunk_size=6)
      result = series.unique().execute().fetch()
      expected = data2.unique()
      np.testing.assert_array_equal(result, expected)
  
      # test md.unique
      result = md.unique(data2).execute().fetch()
      expected = pd.unique(data2)
      np.testing.assert_array_equal(result, expected)
  
      raw_list = list("baabc")
      result = md.unique(raw_list).execute().fetch()
      expected = pd.unique(raw_list)
      np.testing.assert_array_equal(result, expected)
  
      data1 = pd.Series(np.random.randint(0, 5, size=(20,)))
      result = md.unique(data1).execute().fetch()
      expected = pd.unique(data1)
      np.testing.assert_array_equal(result, expected)
  
imports: from typing import NamedTuple
  import numpy
  import pytest
  import pandas
  from ....None import dataframe
  from ....config import option_context
  from ....session import get_default_session
  from ....tests.core import require_cudf, require_cupy
  from ....utils import lazy_import, pd_release_version
  from ...None import CustomReduction, NamedAgg
  from ...base import to_gpu
label_desc: Use image node_id 15 for calling a global function with example usage: test_unique(setup, check_ref_counts) without return types