Workaround for bug in Python 3. See more info at:
        https://bugs.python.org/issue16308
        https://github.com/iterative/dvc/issues/769

        Args:
            subparsers: subparsers to fix.

def fix_subparsers(subparsers):
    """Workaround for bug in Python 3. See more info at:
        https://bugs.python.org/issue16308
        https://github.com/iterative/dvc/issues/769

        Args:
            subparsers: subparsers to fix.
    """
    from dvc.utils.compat import is_py3

    if is_py3:  # pragma: no cover
        subparsers.required = True
        subparsers.dest = "cmd"