text: from collections import namedtuple
  from aslprep.niworkflows.utils.spaces import Reference, SpatialReferences
  from aslprep.workflows.base import init_single_subject_wf
  BIDSLayout = namedtuple('BIDSLayout', ('root'))
  wf = init_single_subject_wf(
      anat_only=False,
      bold2t1w_dof=9,
      cifti_output=False,
      debug=False,
      dummy_scans=None,
      echo_idx=None,
      fmap_bspline=False,
      fmap_demean=True,
      force_syn=True,
      freesurfer=True,
      hires=True,
      ignore=[],
      layout=BIDSLayout('.'),
      longitudinal=False,
      low_mem=False,
      medial_surface_nan=False,
      name='single_subject_wf',
      omp_nthreads=1,
      output_dir='.',
      reportlets_dir='.',
      skull_strip_fixed_seed=False,
      skull_strip_template=Reference('OASIS30ANTs'),
      spaces=SpatialReferences(
          spaces=[('MNI152Lin', {}),
                  ('fsaverage', {'density': '10k'}),
                  ('T1w', {}),
                  ('fsnative', {})],
          checkpoint=True),
      subject_id='test',
      t2s_coreg=False,
      task_id='',
      use_bbr=True,
      use_syn=True,
      bids_filters=None,
      pcasl=pcasl,
  )