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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 reg_score_function(X, y, mean, scale, shape, skewness):
 """ GAS Poisson Regression Update term using gradient only - native Python function Parameters X : float datapoint for the right hand side variable y : float datapoint for the time series mean : float location parameter for the Poisson distribution scale : float scale parameter for the Poisson distribution shape : float tail thickness parameter for the Poisson distribution skewness : float skewness parameter for the Poisson distribution Returns - Score of the Poisson family """

        return X*(y-mean)