<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def udf(f):
 """Create a SQLite scalar UDF from `f` Parameters f A callable object Returns ------- callable A callable object that returns ``None`` if any of its inputs are ``None``. """


    @functools.wraps(f)
    def wrapper(*args):
        if any(arg is None for arg in args):
            return None
        return f(*args)

    _SQLITE_UDF_REGISTRY.add(wrapper)
    return wrapper