appium 1.5，在截图时，经常遇到卡顿现象，咋解？有遇到过类似情况的同学吗？

[debug] [UIAuto] Sending command to instruments: au.capture('screenshotb2ee6957-84c1-4f9a-a861-99f039a7efbf')
[debug] [Instruments] [INST] 2017-04-06 07:24:14 +0000 Debug: evaluation finished
[debug] [Instruments] [INST] 2017-04-06 07:24:14 +0000 Debug: responding with:
[debug] [Instruments] [INST] 2017-04-06 07:24:14 +0000 Debug: Running system command #8: /usr/local/Cellar/node/6.3.0/bin/node /usr/local/lib/node_modules/appium/node_modules/appium-ios-driver/node_modules/appium-uiauto/build/lib/bin/command-proxy-client.js /var/folders/sq/9tbj9l214qsfnjb1qh9x_nrr0000gn/T/instruments_sock 2,{"status":0,"value":""}...

注：每条 case 中每个步骤都会截图，不知是不是截图太过频繁的缘故，还是其他原因