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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 nonparabolicity(self, **kwargs):
        '''
        Returns the Kane band nonparabolicity parameter for the Gamma-valley.
        '''
        Eg = self.Eg_Gamma(**kwargs)
        meff = self.meff_e_Gamma(**kwargs)
        T = kwargs.get('T', 300.)
        return k*T/Eg * (1 - meff)**2