docs: @Nullable
      public Card getCard() {
          String cardNumber = mCardNumberEditText.getCardNumber();
          int[] cardDate = mExpiryDateEditText.getValidDateFields();
          if (cardNumber == null || cardDate == null || cardDate.length != 2) {
              return null;
          }
  
          // CVC/CVV is the only field not validated by the entry control itself, so we check here.
          String cvcValue = mCvcNumberEditText.getText().toString().trim();
          if (!isCvcLengthValid()) {
              return null;
          }
  
          return new Card(cardNumber, cardDate[0], cardDate[1], cvcValue)
                  .addLoggingToken(LOGGING_TOKEN);
      }