code: def masks(mask: np.ndarray) -> Sequence[np.ndarray]:
      masks = [mask]
      mask2 = mask.copy()
      mask2[0, 0, 0] = 1
      masks.append(mask2)
      mask3 = mask.copy()
      mask3[2, 2, 2] = 0
      masks.append(mask3)
      return masks
  
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 7 for calling a global function with example usage: masks(mask) and returns: masks