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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def needkwargs(*argnames):
 """Function decorator which checks that the decorated function is called with a set of required kwargs. Args: *argnames: String keyword argument names. Raises: ValueError: If a required kwarg is missing in the decorated function call. """

    required = set(argnames)

    def decorator(func):
        def inner(*args, **kwargs):
            missing = required - set(kwargs)
            if missing:
                err = "%s kwargs are missing." % list(missing)
                raise ValueError(err)
            return func(*args, **kwargs)
        return inner
    return decorator