Output of running 'should resize the current viewport' test

output.log

1) Homepage should resize the current viewport:
A request to use a window could not be satisfied because the window could not be found. (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 4 milliseconds
Build info: version: '3.0.1', revision: '1969d75', time: '2016-10-18 09:48:19 -0700'
System info: host: 'Horias-MBP.ws2.tem.nl', ip: '10.41.1.217', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.12.4', java.version: '1.8.0_121'
Driver info: org.openqa.selenium.safari.SafariDriver
Capabilities [{applicationCacheEnabled=true, rotatable=false, databaseEnabled=true, handlesAlerts=true, version=12603.1.30.0.34, cleanSession=true, platform=MAC, nativeEvents=true, locationContextEnabled=false, webStorageEnabled=true, browserName=safari, javascriptEnabled=true, platformName=macOS, cssSelectorsEnabled=true}]
Session ID: ADDE9E66-40FB-4244-B96F-71A7ED00C70E
running safari
Error: A request to use a window could not be satisfied because the window could not be found. (WARNING: The server did not provide any stacktrace information)
    at Context.<anonymous> (test/specs/test.js:23:17)
    at Promise.F (node_modules/core-js/library/modules/_export.js:35:28)
    Command duration or timeout: 4 milliseconds
    Build info: version: '3.0.1', revision: '1969d75', time: '2016-10-18 09:48:19 -0700'
    System info: host: 'Horias-MBP.ws2.tem.nl', ip: '10.41.1.217', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.12.4', java.version: '1.8.0_121'
    Driver info: org.openqa.selenium.safari.SafariDriver
    Capabilities [{applicationCacheEnabled=true, rotatable=false, databaseEnabled=true, handlesAlerts=true, version=12603.1.30.0.34, cleanSession=true, platform=MAC, nativeEvents=true, locationContextEnabled=false, webStorageEnabled=true, browserName=safari, javascriptEnabled=true, platformName=macOS, cssSelectorsEnabled=true}]
    Session ID: ADDE9E66-40FB-4244-B96F-71A7ED00C70E
    at windowHandleSize([object Object]) - setViewportSize.js:87:26