func (s *Session) SetSyncTimeout(d time.Duration) {
	s.m.Lock()
	s.syncTimeout = d
	s.m.Unlock()
}
func (s *Session) SetSyncTimeout(d time.Duration) {
	s.m.Lock()
	s.syncTimeout = d
	s.m.Unlock()
}
// SetSyncTimeout sets the amount of time an operation with this session
// will wait before returning an error in case a connection to a usable
// server can't be established. Set it to zero to wait forever. The
// default value is 7 seconds.