code: def _mixed_morph_srcs():
      pytest.importorskip("nibabel")
      pytest.importorskip("dipy")
      # create a mixed source space
      labels_vol = ["Left-Cerebellum-Cortex", "Right-Cerebellum-Cortex"]
      src = mne.setup_source_space(
          "sample",
          spacing="oct3",
          add_dist=False,
          subjects_dir=subjects_dir,
      )
      src += mne.setup_volume_source_space(
          "sample",
          mri=fname_aseg,
          pos=10.0,
          volume_label=labels_vol,
          subjects_dir=subjects_dir,
          add_interpolator=True,
          verbose=True,
      )
      # create the destination space
      src_fs = mne.read_source_spaces(
          subjects_dir / "fsaverage" / "bem" / "fsaverage-ico-5-src.fif"
      )
      src_fs += mne.setup_volume_source_space(
          "fsaverage",
          pos=7.0,
          volume_label=labels_vol,
          subjects_dir=subjects_dir,
          add_interpolator=False,
          verbose=True,
      )
      del labels_vol
  
      with pytest.raises(
          ValueError, match="src_to must be provided .* mixed"
      ):
          mne.compute_source_morph(
              src=src,
              subject_from="sample",
              subject_to="fsaverage",
              subjects_dir=subjects_dir,
          )
  
      with pytest.warns(
          RuntimeWarning, match="not included in smoothing"
      ):
          morph = mne.compute_source_morph(
              src=src,
              subject_from="sample",
              subject_to="fsaverage",
              subjects_dir=subjects_dir,
              niter_affine=[1, 0, 0],
              niter_sdr=[1, 0, 0],
              src_to=src_fs,
              smooth=5,
              verbose=True,
          )
      return morph, src, src_fs
  
imports: from inspect import signature
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal, assert_array_less
  from scipy.sparse import csr_matrix
  from scipy.sparse import eye
  from scipy.spatial.distance import cdist
  import mne
  from mne import SourceEstimate, SourceMorph, VectorSourceEstimate, VolSourceEstimate, VolVectorSourceEstimate, compute_source_morph, get_volume_labels_from_aseg, grade_to_vertices, make_ad_hoc_cov, make_forward_solution, make_sphere_model, read_evokeds, read_forward_solution, read_freesurfer_lut, read_source_estimate, read_source_morph, setup_volume_source_space
  from mne._freesurfer import _get_atlas_values, _get_mri_info_data
  from mne.datasets import testing
  from mne.fixes import _get_img_fdata
  from mne.minimum_norm import apply_inverse, make_inverse_operator, read_inverse_operator
  from mne.source_space._source_space import _add_interpolator, _grid_interp
  from mne.transforms import quat_to_rot
  from mne.utils import _record_warnings, catch_logging
label_desc: Use image node_id 14 for calling a global function with example usage: _mixed_morph_srcs() and returns: morph,  src,  src_fs