@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_calculator);
        mCalculator = new Calculator();
        mResultTextView = (TextView) findViewById(R.id.operation_result_text_view);
        mOperandOneEditText = (EditText) findViewById(R.id.operand_one_edit_text);
        mOperandTwoEditText = (EditText) findViewById(R.id.operand_two_edit_text);
    }
{@link android.app.Activity} which contains a simple calculator. Numbers can be entered in the
two {@link EditText} fields and result can be obtained by pressing one of the
operation {@link Button}s at the bottom.
runner/AndroidTestOrchestratorWithTestCoverageSample/app/src/main/java/com/example/android/testing/androidtestorchestratorsample/CalculatorActivity.java