Imports github.com/juju/errors github.com/juju/loggo github.com/juju/mgo/v2 github.com/juju/mgo/v2/bson github.com/juju/mgo/v2/txn github.com/juju/txn/v2 github.com/juju/utils/v3 Standard library imports crypto/sha512 fmt io io/ioutil math/rand os path strings sync time