REF: add method get_parser()
REF: add method get_parser()

Former-commit-id: bb3605214bf60c1eb3fa36ef58ae8fec7b9bc5f4
Former-commit-id: dc02f20a04192dd62e0dca52c6f9310cad4854db
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox