code: def test_errors():
      masker = NiftiSpheresMasker(([1, 2]), radius=0.2)
      with pytest.raises(ValueError, match="Seeds must be a list .+"):
          masker.fit()
  
imports: import warnings
  import nibabel
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from nilearn._utils import data_gen
  from nilearn.image import get_data, new_img_like
  from nilearn.maskers import NiftiSpheresMasker
label_desc: Use image node_id 4 for calling a global function with example usage: test_errors() without return types