code: def test_selector_unique(
      columns: tp.List[str], expected: tp.Iterable[tp.Tuple[int, int]]
  ) -> None:
      df = utils.Selector(
          index=["i1", "i2", "i3"],
          columns=["c1", "c2"],
          data=[[2, 1], [2, 2], [2, 1]],
      )
      testing.printed_assert_equal(df.unique(columns), expected)
  
file_path: nevergrad/nevergrad/benchmark/test_utils.py
imports: import itertools
  import typing
  import numpy
  from nevergrad.common import testing
  from .None import utils
label_desc: Use image node_id 2 for calling a global function with example usage: test_selector_unique(columns, expected) without return types