public void onSaveClick(View view) {
        // Don't save if the fields do not validate.
        if (!mEmailValidator.isValid()) {
            mEmailText.setError("Invalid email");
            Log.w(TAG, "Not saving personal information: Invalid email");
            return;
        }

        // Get the text from the input fields.
        String name = mNameText.getText().toString();
        Calendar dateOfBirth = Calendar.getInstance();
        dateOfBirth.set(mDobPicker.getYear(), mDobPicker.getMonth(), mDobPicker.getDayOfMonth());
        String email = mEmailText.getText().toString();

        // Create a Setting model class to persist.
        SharedPreferenceEntry sharedPreferenceEntry =
                new SharedPreferenceEntry(name, dateOfBirth, email);

        // Persist the personal information.
        boolean isSuccess = mSharedPreferencesHelper.savePersonalInfo(sharedPreferenceEntry);
        if (isSuccess) {
            Toast.makeText(this, "Personal information saved", Toast.LENGTH_LONG).show();
            Log.i(TAG, "Personal information saved");
        } else {
            Log.e(TAG, "Failed to write personal information to SharedPreferences");
        }
    }
Called when the "Save" button is clicked.
unit/BasicSample/app/src/main/java/com/example/android/testing/unittesting/BasicSample/MainActivity.java