code: @NonNull
      public static SourceParams createBancontactParams(
              @IntRange(from = 0) long amount,
              @NonNull String name,
              @NonNull String returnUrl,
              @Nullable String statementDescriptor,
              @Nullable String preferredLanguage) {
          final SourceParams params = new SourceParams()
                  .setType(Source.BANCONTACT)
                  .setCurrency(Source.EURO)
                  .setAmount(amount)
                  .setOwner(createSimpleMap(FIELD_NAME, name))
                  .setRedirect(createSimpleMap(FIELD_RETURN_URL, returnUrl));
  
          if (statementDescriptor != null || preferredLanguage != null) {
              final AbstractMap<String, Object> additionalParamsMap = new HashMap<>();
  
              additionalParamsMap.put(FIELD_STATEMENT_DESCRIPTOR, statementDescriptor);
              additionalParamsMap.put(FIELD_PREFERRED_LANGUAGE, preferredLanguage);
              removeNullAndEmptyParams(additionalParamsMap);
  
              params.setApiParameterMap(additionalParamsMap);
          }
  
          return params;
      }
docs: Create parameters necessary for creating a Bancontact source.
  
  @param amount A positive integer in the smallest currency unit representing the amount to
  charge the customer (e.g., 1099 for a €10.99 payment). The charge amount must be
  at least €1 or its equivalent in the given currency.
  @param name The full name of the account holder.
  @param returnUrl The URL the customer should be redirected to after the authorization
  process.
  @param statementDescriptor A custom statement descriptor for the payment (optional).
  @param preferredLanguage The preferred language of the Bancontact authorization page that the
  customer is redirected to. Supported values are: en, de, fr, or nl
  (optional).
  @return a {@link SourceParams} object that can be used to create a Bancontact source
  
  @see <a href="https://stripe.com/docs/sources/bancontact">https://stripe.com/docs/sources/bancontact</a>