whois groups.google.com/g/sebastian-lonnbergg/c/5e3g0mD75VU/

Domain:
Turn off cache
Try for webbased whois (don't expect it to work yet)
groups.google.com/g/sebastian-lonnbergg/c/5e3g0mD75VU/
checking....groups.google.com/g/sebastian-lonnbergg/c/5e3g0mD75VU/
   $ whois groups.google.com/g/sebastian-lonnbergg/c/5e3g0mD75VU/
No whois server is known for this kind of object.