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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 validate_key(func):
 """ Decorator to validate a key for zookeeper. """


    @wraps(func)
    def wrapper(self, key, *args, **kwargs):
        if posixpath.sep in key:
            raise ValueError('Keys cannot contains slashes')

        return func(self, key, *args, **kwargs)

    return wrapper