E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.facci.testingnetwork, PID: 6103
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.facci.testingnetwork/com.facci.testingnetwork.MainActivity}: java.lang.RuntimeException: com.facci.testingnetwork.MainActivity@49faa6 must implement OnFragmentInteractionListener
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2749)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2810)
        at android.app.ActivityThread.-wrap12(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6312)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:872)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:762)
     Caused by: java.lang.RuntimeException: com.facci.testingnetwork.MainActivity@49faa6 must implement OnFragmentInteractionListener
        at com.facci.testingnetwork.MainFragment.onAttach(MainFragment.java:83)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1404)
        at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1195)
        at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:1078)
        at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:117)
        at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2408)
        at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
        at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2273)
        at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3273)
        at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:3229)
        at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:201)
        at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:620)
        at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:178)
        at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1249)
        at android.app.Activity.performStart(Activity.java:6774)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2712)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2810)
        at android.app.ActivityThread.-wrap12(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6312)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:872)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:762)