docs: def skull_strip(dset,suffix='_ns',prefix=None,unifize=True):
      ''' use bet to strip skull from given anatomy '''
      # should add options to use betsurf and T1/T2 in the future
      # Since BET fails on weirdly distributed datasets, I added 3dUnifize in... I realize this makes this dependent on AFNI. Sorry, :)
      if prefix==None:
          prefix = nl.suffix(dset,suffix)
      unifize_dset = nl.suffix(dset,'_u')
      cmd = bet2 if bet2 else 'bet2'
      if unifize:
          info = nl.dset_info(dset)
          if info==None:
              nl.notify('Error: could not read info for dset %s' % dset,level=nl.level.error)
              return False
          cmd = os.path.join(fsl_dir,cmd) if fsl_dir else cmd
          cutoff_value = nl.max(dset) * 0.05
          nl.run(['3dUnifize','-prefix',unifize_dset,nl.calc(dset,'step(a-%f)*a' % cutoff_value)],products=unifize_dset)
      else:
          unifize_dset = dset
      nl.run([cmd,unifize_dset,prefix,'-w',0.5],products=prefix)