e);     std::string description("Hessian of Gaussian (flattened upper triangular matrix), scale=");     description += asString(sigma);          res.reshapeIfEmpty(image.taggedShape().setChannelDescription(description),               "hessianOfGaussian(): Output array has wrong shape.");          {         PyAllowThreads _pythread;         hessianOfGaussianMultiArray(srcMultiArrayRange(