from qsiprep.workflows.dwi.fsl import init_fsl_hmc_wf
wf = init_fsl_hmc_wf({'dwi_series':['dwi1.nii', 'dwi2.nii'],
                            'fieldmap_info': {'suffix': None},
                            'dwi_series_pedir': 'j'},
                     b0_threshold=100,
                     impute_slice_threshold=0.,
                     fmap_demean=False,
                     fmap_bspline=False,
                     eddy_config=None,
                     source_file='/path/to/dwi/sub-X_dwi.nii.gz',
                     omp_nthreads=1)