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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 acq(self, graph):
        ''' estimate the value of generated graph
        '''
        mean, std = self.gpr.predict(np.array([graph.extract_descriptor()]))
        if self.optimizemode is OptimizeMode.Maximize:
            return mean + self.beta * std
        return mean - self.beta * std