     isSpec = true
     devMode = true
     safeMode ?= false
-    new AtomWindow({bootstrapScript, resourcePath, exitWhenDone, isSpec, devMode, specDirectory, logFile, safeMode})
+    apiPreviewMode ?= false
+    new AtomWindow({bootstrapScript, resourcePath, exitWhenDone, isSpec, devMode, specDirectory, logFile, safeMode, apiPreviewMode})
 
   runBenchmarks: ({exitWhenDone, specDirectory}={}) ->
     try

  #   :specPath - The directory to load specs from.
  #   :safeMode - A Boolean that, if true, won't run specs from ~/.atom/packages
  #               and ~/.atom/dev/packages, defaults to false.
  runSpecs: ({exitWhenDone, resourcePath, specDirectory, logFile, safeMode}) ->
    if resourcePath isnt @resourcePath and not fs.existsSync(resourcePath)
      resourcePath = @resourcePath



  openWithOptions: ({pathsToOpen, urlsToOpen, test, pidToKillWhenClosed, devMode, safeMode, apiPreviewMode, newWindow, specDirectory, logFile, profileStartup}) ->
    if test
      @runSpecs({exitWhenDone: true, @resourcePath, specDirectory, logFile, apiPreviewMode})
    else if pathsToOpen.length > 0
      @openPaths({pathsToOpen, pidToKillWhenClosed, newWindow, devMode, safeMode, apiPreviewMode, profileStartup})
    else if urlsToOpen.length > 0
