Can not find vtkVolumeRayCastMIPFunction in vtk 9.1

I want to implement maximum intensity projection in my project, and vtkVolumeRayCastMIPFunction is what I want. However, I can not find it in vtk 9.1. Is there any method can replace vtkVolumeRayCastMIPFunction? Or how can I implement MIP in vtk 9.1?

Any suggestion is appreciated~~~