docs: @Override
      public JobIntentService.GenericWorkItem dequeueWork() {
          JobWorkItem work = null;
          synchronized (mLock) {
              if (mParams == null) {
                  return null;
              }
              try {
                  work = mParams.dequeueWork();
              } catch (SecurityException se) {
                  //ignore
                  se.printStackTrace();
              }
          }
          if (work != null) {
              work.getIntent().setExtrasClassLoader(mService.getClassLoader());
              return new WrapperWorkItem(work);
          } else {
              return null;
          }
      }