@Test
    public void divTwoNumbers() {
        double resultDiv = mCalculator.div(32d,2d);
        assertThat(resultDiv).isEqualTo(16d);
    }
JUnit4 unit tests for the calculator logic.
runner/AndroidJunitRunnerSample/app/src/androidTest/java/com/example/android/testing/androidjunitrunnersample/CalculatorTest.java