@Test
    public void useAppContext() {
        // Context of the app under test.
        Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
        assertEquals("com.example.vcam", appContext.getPackageName());
    }
Instrumented test, which will execute on an Android device.

@see <a href="http://d.android.com/tools/testing">Testing documentation</a>
app/src/androidTest/java/com/example/vcam/ExampleInstrumentedTest.java