server.go
func (s *Server) NumNodes() int {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.numNodes()
}
func (s *Server) NumNodes() int {
	s.mu.Lock()
	defer s.mu.Unlock()
	return s.numNodes()
}
func ( s * Server ) NumNodes ( ) int { s . mu . Lock ( ) defer s . mu . Unlock ( ) return s . numNodes ( ) }
// Returns how many nodes are in the node table.
Returns how many nodes are in the node table .