// java.lang.IllegalStateException: Fragment has not been attached yet.
// at android.support.v4.app.Fragment.instantiateChildFragmentManager(Fragment.java:2154)
// at android.support.v4.app.Fragment.getChildFragmentManager(Fragment.java:704)
// at de.tap.easy_xkcd.fragments.whatIf.WhatIfOverviewFragment$GetDoc.onPostExecute(WhatIfOverviewFragment.java:143)
// at de.tap.easy_xkcd.fragments.whatIf.WhatIfOverviewFragment$GetDoc.onPostExecute(WhatIfOverviewFragment.java:109)
// at android.os.AsyncTask.finish(AsyncTask.java:651)
// at android.os.AsyncTask.-wrap1(AsyncTask.java)
// at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
// at android.os.Handler.dispatchMessage(Handler.java:102)
// at android.os.Looper.loop(Looper.java:148)
// at android.app.ActivityThread.main(ActivityThread.java:5417)
// at java.lang.reflect.Method.invoke(Native Method)
// at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
// at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)