Stayed on loading, about example

[wpecker]

$ nodejs -v                                                          
v4.8.2

$ node -v  
v7.10.1

$ npm -v                                                                                   
4.2.0

$ go version 
go version go1.11 linux/amd64

$git:(master*) ./go-diagram example1  
Listening on http://localhost:4442
Begin websocket server
Process 2 directories
Pushing file change to client.
Detected file change <nil>
Process 2 directories
Pushing file change to client.