code: def test_interval_index_unique():
      interval_list = [
          np.nan,
          pd.Interval(2.0, 3.0, closed="right"),
          pd.Interval(3.0, 4.0, closed="right"),
          np.nan,
          pd.Interval(3.0, 4.0, closed="right"),
          pd.Interval(3.0, 4.0, closed="right"),
      ]
      pi = pd.Index(interval_list)
      gi = cudf.from_pandas(pi)
  
      expected = pi.unique()
      actual = gi.unique()
  
      assert_eq(expected, actual)
  
file_path: cudf/python/cudf/cudf/tests/test_interval.py
imports: import numpy
  import pandas
  import pytest
  import cudf
  from cudf.testing._utils import assert_eq
label_desc: Use image node_id 4 for calling a global function with example usage: test_interval_index_unique() without return types