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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 hessfunc(self, p):
 """ The Hessian function that will be passed to the optimizer, if needed. """

        self._set_stochastics(p)
        for i in xrange(self.len):

            di = self.diff(i)
            self.hess[i, i] = self.diff(i, 2)

            if i < self.len - 1:

                for j in xrange(i + 1, self.len):
                    dij = self.diff2(i, j)

                    self.hess[i, j] = dij
                    self.hess[j, i] = dij

        return -1. * self.hess