def _as_list(obj):
if type(obj) in (tuple, set, list):<EOL><INDENT>return obj<EOL><DEDENT>else:<EOL><INDENT>return [obj]<EOL><DEDENT>
Returns an object as a list.

    Ensure that the object type is tuple, set or list, if not put the element
    in a list and return this new list.

    Args:
        obj: Object you want to check.
    Returns:
        An iterable with type tuple, set or list.