not implemented: CREATE RETENTION POLICY

[mfaizan1]

I am trying to create a retention policy on a bucket using the command
CREATE RETENTION POLICY "2year" ON "bucketname" DURATION 94w REPLICATION 1;
but I get this error

Error: not implemented: CREATE RETENTION POLICY

if i pass some invalid arguments shell tells me there is an issue with the command but when it seems correct it doesn't work at all.