package com.example.stimulusStrategy; import android.app.Service; import android.content.Intent; import android.os.IBinder; import android.support.annotation.Nullable; import com.example.stimulus.Stimulus; import java.util.Observable; import java.util.Observer; /** * Created by pharmacy on 09/01/2018. */ public class LockScreenActivity extends Service implements StimulusStrategy { public void monitor() { //Monitor a thing } @Nullable @Override public IBinder onBind(Intent intent) { return null; } }