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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 diffusion_driver(self):
 """ diffusion driver are the underlying `dW` of each process `X` in a SDE like `dX = m dt + s dW` :return list(StochasticProcess):
 """

        if self._diffusion_driver is None:
            return self,
        if isinstance(self._diffusion_driver, list):
            return tuple(self._diffusion_driver)
        if isinstance(self._diffusion_driver, tuple):
            return self._diffusion_driver
        return self._diffusion_driver,