session copy

session.go

@@ -14,6 +14,10 @@ func (s *Session) Close() {
 	s.session.Close()
 }
 
+func (s *Session) Copy() *Session {
+	return &Session{session: s.session.Copy()}
+}
+
 func NewSession(dial string) (*Session, error) {
 	session, err := mgo.Dial(dial)
 	if err != nil {