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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 isset(name):
 """Only execute the function if the variable is set. Args: name: The name of the environment variable Returns: The function return value or `None` if the function was skipped. """

    def wrapped(func):
        @functools.wraps(func)
        def _decorator(*args, **kwargs):
            if core.isset(name):
                return func(*args, **kwargs)
        return _decorator
    return wrapped