e);     std::string description("Hessian of Gaussian (flattened upper triangular matrix), scale=");     description += asString(sigma);          res.reshapeIfEmpty(volume.taggedShape().setChannelDescription(description),            "hessianOfGaussian(): Output array has wrong shape.");          {         PyAllowThreads _pythread;         hessianOfGaussianMultiArray(srcMultiArrayRange(volume), destMultiArray(res), params());     }          return res; }  template < class PixelType> NumpyAnyArray  pythonHessianOfGaussian0D(NumpyArray<0, Singleband<PixelType> > image,                           python::object sigma,                           NumpyArray<0, TinyVector<