win7 下使用 android 真机连接，运行 macaca 官方例子 (macaca-test-sample-master) 中 macaca-mobile-sample.test.js 报这个错，请各位高手求解？
macaca mobile sample "before all" hook:
[init({"autoAcceptAlerts":true,"platformName":"Android","udid":"177fc4b2","
pp":"C:\Users\weiqh\macaca-test-sample-master\app\android-app-bootstrap.zi
"})] connect ECONNREFUSED 127.0.0.1:3456
Error: connect ECONNREFUSED 127.0.0.1:3456
at Object.exports._errnoException (util.js:953:11)
at exports._exceptionWithHostPort (util.js:976:20)
at TCPConnectWrap.afterConnect as oncomplete

2) macaca mobile sample "after all" hook:
[quit()] connect ECONNREFUSED 127.0.0.1:3456
Error: connect ECONNREFUSED 127.0.0.1:3456
at Object.exports._errnoException (util.js:953:11)
at exports._exceptionWithHostPort (util.js:976:20)
at TCPConnectWrap.afterConnect as oncomplete