when a version is not specified, add .to_s when it tries to get the current version, because in some system the attributes hash uses strings and in another ones uses symbols
when a version is not specified, add .to_s when it tries to get the current version, because in some system the attributes hash uses strings and in another ones uses symbols

Yakrware/mongoid-history,aq1018/mongoid-history,dblock/mongoid-history,mongoid/mongoid-history,getaroom/mongoid-history,mateuspontes/mongoid-history,sivagollapalli/mongoid-history,stephenhmarsh/mongoid-history