E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.patryk.android4/com.example.patryk.android4.MainActivity}: java.lang.ClassCastException: com.example.patryk.android4.FragmentOne cannot be cast to android.support.v4.app.Fragment
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            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:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.ClassCastException: com.example.patryk.android4.FragmentOne cannot be cast to android.support.v4.app.Fragment
            at android.support.v4.app.Fragment.instantiate(Fragment.java:420)
            at android.support.v4.app.Fragment.instantiate(Fragment.java:395)
            at com.example.patryk.android4.TabListener.onTabSelected(TabListener.java:30)
            at android.support.v7.internal.app.WindowDecorActionBar.selectTab(WindowDecorActionBar.java:634)
            at android.support.v7.internal.app.WindowDecorActionBar.addTab(WindowDecorActionBar.java:563)
            at android.support.v7.internal.app.WindowDecorActionBar.addTab(WindowDecorActionBar.java:549)
            at com.example.patryk.android4.MainActivity.onCreate(MainActivity.java:34)
            at android.app.Activity.performCreate(Activity.java:5008)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            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:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)