def _list_outputs(self):
    outputs = super(VolSymm, self)._list_outputs()
    if os.path.exists(outputs['trans_file']):
        if ('grid' in open(outputs['trans_file'], 'r').read()):
            outputs['output_grid'] = re.sub('.(nlxfm|xfm)$', '_grid_0.mnc', outputs['trans_file'])
    return outputs
def _list_outputs(self):
    outputs = super(VolSymm, self)._list_outputs()
    if os.path.exists(outputs['trans_file']):
        if ('grid' in open(outputs['trans_file'], 'r').read()):
            outputs['output_grid'] = re.sub('.(nlxfm|xfm)$', '_grid_0.mnc', outputs['trans_file'])
    return outputs