class MainActivity extends AppCompatActivity {

    @VisibleForTesting
    void initViews() {
        EditText weightText = (EditText)findViewById(R.id.text_weight);
        EditText heightText = (EditText)findViewById(R.id.text_height);
        TextView resultText = (TextView)findViewById(R.id.text_result);

        mCalcButton = (Button)findViewById(R.id.button_calculate);

        View.OnClickListener buttonListener = createButtonListener(weightText, heightText, resultText);
        mCalcButton.setOnClickListener(buttonListener);
    }

}