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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 derivative(self, x):
 """Return the operator derivative at ``x``. The derivative of a sum of two operators is equal to the sum of the derivatives. Parameters x : `domain` `element-like` Evaluation point of the derivative """

        if self.is_linear:
            return self
        else:
            return OperatorSum(self.left.derivative(x),
                               self.right.derivative(x),
                               self.__tmp_dom, self.__tmp_ran)