docs: public void clear() {
          mCardNumberEditText.setText("");
          mExpiryDateEditText.setText("");
          mCvcEditText.setText("");
          mPostalCodeEditText.setText("");
          mCardNumberEditText.setShouldShowError(false);
          mExpiryDateEditText.setShouldShowError(false);
          mCvcEditText.setShouldShowError(false);
          mPostalCodeEditText.setShouldShowError(false);
          updateBrand(Card.UNKNOWN);
      }