<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ensure_tuple(tuple_or_mixed, *, cls=None):
 """ If it's not a tuple, let's make a tuple of one item. Otherwise, not changed. :param tuple_or_mixed: :return: tuple """

    if cls is None:
        cls = tuple

    if isinstance(tuple_or_mixed, cls):
        return tuple_or_mixed

    if tuple_or_mixed is None:
        return tuple.__new__(cls, ())

    if isinstance(tuple_or_mixed, tuple):
        return tuple.__new__(cls, tuple_or_mixed)

    return tuple.__new__(cls, (tuple_or_mixed,))