def _list_outputs(self):
    outputs = super(XfmConcat, self)._list_outputs()
    if os.path.exists(outputs['output_file']):
        if ('grid' in open(outputs['output_file'], 'r').read()):
            outputs['output_grids'] = glob.glob(re.sub('.(nlxfm|xfm)$', '_grid_*.mnc', outputs['output_file']))
    return outputs
def _list_outputs(self):
    outputs = super(XfmConcat, self)._list_outputs()
    if os.path.exists(outputs['output_file']):
        if ('grid' in open(outputs['output_file'], 'r').read()):
            outputs['output_grids'] = glob.glob(re.sub('.(nlxfm|xfm)$', '_grid_*.mnc', outputs['output_file']))
    return outputs