code: def test_extract_labels(
      self, condition_spec: SingleConditionSpec
  ) -> None:
      assert np.array_equal(
          condition_spec.extract_labels(), np.array([0, 1])
      )
  
imports: from typing import Iterable, Sequence
  import numpy
  import pytest
  from nibabel.nifti1 import Nifti1Pair
  from nibabel.spatialimages import SpatialImage
  from brainiak.image import mask_image, mask_images, MaskedMultiSubjectData, multimask_images, SingleConditionSpec
label_desc: Use image node_id 1 for calling the TestUniqueLabelConditionSpec obj's underlying member method code with example usage: obj.test_extract_labels(condition_spec) without return types