android.util.AndroidRuntimeException: Window feature must be requested before adding content
            at android.support.v7.app.AppCompatDelegateImplV7.throwFeatureRequestIfSubDecorInstalled(AppCompatDelegateImplV7.java:1584)
            at android.support.v7.app.AppCompatDelegateImplV7.requestWindowFeature(AppCompatDelegateImplV7.java:509)
            at android.support.v7.app.AppCompatDelegateImplBase.onCreate(AppCompatDelegateImplBase.java:117)
            at android.support.v7.app.AppCompatDelegateImplV7.onCreate(AppCompatDelegateImplV7.java:148)
            at android.support.v7.app.AppCompatDialog.onCreate(AppCompatDialog.java:60)
            at android.app.Dialog.dispatchOnCreate(Dialog.java:353)
            at android.app.Dialog.show(Dialog.java:257)
            at android.support.v4.app.DialogFragment.onStart(DialogFragment.java:406)
            at android.support.v4.app.Fragment.performStart(Fragment.java:1986)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1051)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1197)
            at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
            at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1562)
            at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:483)
            at android.os.Handler.handleCallback(Handler.java:605)
            at android.os.Handler.dispatchMessage(Handler.java:92)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4424)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
            at dalvik.system.NativeStart.main(Native Method)