ImageLoader Test case

@Test
  fun testImageLoader_returnSuccess() {
    val imageView = activityTestRule.activity.findViewById(R.id.test_url_parser_image_view) as ImageView
    var drawable: Drawable? = null
    val testBitmap: Bitmap? = null
    val target = object : CustomTarget<Bitmap>() {
      override fun onLoadCleared(placeholder: Drawable?) {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
      }
      override fun onResourceReady(resource: Bitmap, transition: Transition<in Bitmap>?) {
        drawable = BitmapDrawable(activityTestRule.activity.getResources(), resource);
        imageView.setImageDrawable(drawable)
      }
    }

    doAnswer(Answer() {
      fun answer(invocation: InvocationOnMock) {
        invocation.getArgument<CustomTarget<Bitmap>>(1).onResourceReady(testBitmap!!, null)
        imageView.setImageBitmap(testBitmap)

      }
    }).`when`(imageLoader).load(OK_IMAGE_URL, target)
  }