How to identify a stream type?

Refer to this in Stackoverflow

https://stackoverflow.com/questions/63663568/how-do-i-set-metadata-in-the-peerjs-peer-callid-stream-options-function

We can add metadata to a ``call``. But can we add metadata to a ``stream``?

Because we can actually add all voice + video + screen sharing into one call.

Are we suppose to use different call for different stream?