Because instrumented tests are built into an APK (separate from your app APK), they must have their own file. However, Gradle automatically generates this file during the build so it is not visible in your project source set. You can add your own manifest file if necessary, such as to specify a different value for `minSdkVersion` or register run listeners just for your tests. When building your app, Gradle merges multiple manifest files into one manifest. The Gradle build interprets these test source sets in the same manner as it does for your project's app source sets , which allows you to create tests based on build variants .
With the first few test images, you can calibrate your monitor by adjusting the brightness, contrast, clock/phase, sharpness, and gamma settings of the monitor. I recommend to go through them in the order they are presented. If you use this page in a shop, don't assume that the contrast and other settings are at reasonable values before making a judgement. The images are best viewed in a dim or dark environment and in full-screen mode. In most browsers, F11 switches to full-screen mode. If switching off the lights is not possible, try using a piece of cardboard to shield environmental light.