How to obtain spin force information in Sunny.jl?

Hi, I am trying to extract spin force information from Sunny.jl. For a given System, it is straightforward to access spin configurations and total energy, but I could not figure out how to obtain the spin force (-\partial E / \partial S). I noticed that in system there exists a dipole_buffers array, which contains six elements, and each element is a 4-dimensional Array. Does one of these correspond to the spin force? If not, what is the recommended way to access the spin force within Sunny? Thanks a lot for your help!