code: def _conform_mask(in_mask, in_reference):
      
      from pathlib import Path
      import nibabel as nb
      from nipype.utils.filemanip import fname_presuffix
  
      ref = nb.load(in_reference)
      nii = nb.load(in_mask)
      hdr = nii.header.copy()
      hdr.set_data_dtype('int16')
      hdr.set_slope_inter(1, 0)
  
      qform, qcode = ref.header.get_qform(coded=True)
      if qcode is not None:
          hdr.set_qform(qform, int(qcode))
  
      sform, scode = ref.header.get_sform(coded=True)
      if scode is not None:
          hdr.set_sform(sform, int(scode))
  
      if '_maths' in in_mask:  # Cut the name at first _maths occurrence
          ext = ''.join(Path(in_mask).suffixes)
          basename = Path(in_mask).name
          in_mask = basename.split('_maths')[0] + ext
  
      out_file = fname_presuffix(in_mask, suffix='_mask',
                                 newpath=str(Path()))
      nii.__class__(nii.get_data().astype('int16'), ref.affine,
                    hdr).to_filename(out_file)
      return out_file
docs: Ensures the mask headers make sense and match those of the T1w