"Hello, I am a newcomer to GWCS, and I am currently trying to create a world coordinate system for the Magellanic Stream using GWCS, and I hope to reproject data from other coordinate systems into this coordinate system, but it seems quite challenging. I have looked through the GWCS documentation, but there don't seem to be any complex examples. The SkyCoordinate for the Magellanic Stream is defined in gala.coordinates.magellanic_stream and is described at Tools. Can you provide some examples and advice?