code: function smove(source, destination, member, req) {
    var src = this.getKey(source, req)
      , dest = this.getKey(destination, req);
    if(src === undefined || !src.sismember(member)) return 0;
    if(dest === undefined) {
      dest = new Set();
      this.setKey(destination, dest, undefined, undefined, undefined, req);
    }
    //console.dir(member);
    src.delKey(member);
    dest.sadd([member]);
    if(src.scard() === 0) {
      this.delKey(source, req);
    }
    return 1;
  }
docs: Move member from the set at source to the set at destination.