Godeps/_workspace/src/gopkg.in/mgo.v2/session.go
func (db *Database) With(s *Session) *Database {
	newdb := *db
	newdb.Session = s
	return &newdb
}
func (db *Database) With(s *Session) *Database {
	newdb := *db
	newdb.Session = s
	return &newdb
}
// With returns a copy of db that uses session s.