How to distinguish different NVSwitch?


I assume that there can be several NVSwitch used in the same machine? If so, how to distinguish them, to be able to know which GPUs are connected through the same NVSwitch?

I know for instance that for NVLinks, one can use nvmlDeviceGetNvLinkRemotePciInfo to get the id of the PCI card that is at the other end of the NVLink, but for NVSwitches, how do we get the ID of the NVSwitch each GPU is connected to?