Add /payment/method input

Added new method field to specify the payment method associated with
the transaction. The method field accepts values like CARD,
DIGITAL_WALLET, BUY_NOW_PAY_LATER, CRYPTO, and others, serialized as
lowercase with underscores in JSON requests.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: horgh

CHANGELOG.md

@@ -18,6 +18,9 @@ CHANGELOG
 * Added the input `/event/party`. This is the party submitting the
   transaction. You may provide this using the `party` method on
   `Event.Builder`.
+* Added the input `/payment/method`. This is the payment method associated
+  with the transaction. You may provide this using the `method` method on
+  `Payment.Builder`.
 
 3.9.0
 ------------------

README.md

@@ -197,6 +197,7 @@ Transaction request = new Transaction.Builder(
     ).payment(
         new Payment.Builder()
             .declineCode("invalid")
+            .method(Payment.Method.CARD)
             .processor(Payment.Processor.ADYEN)
             .wasAuthorized(false)
             .build()

src/main/java/com/maxmind/minfraud/request/Payment.java

@@ -7,11 +7,13 @@
  * The payment information for the transaction.
  */
 public final class Payment extends AbstractModel {
+    private final Method method;
     private final Processor processor;
     private final Boolean wasAuthorized;
     private final String declineCode;
 
     private Payment(Payment.Builder builder) {
+        method = builder.method;
         processor = builder.processor;
         wasAuthorized = builder.wasAuthorized;
         declineCode = builder.declineCode;
@@ -22,10 +24,20 @@ private Payment(Payment.Builder builder) {
      * methods.
      */
     public static final class Builder {
+        Method method;
         Processor processor;
         Boolean wasAuthorized;
         String declineCode;
 
+        /**
+         * @param method The payment method used for the transaction.
+         * @return The builder object.
+         */
+        public Payment.Builder method(Method method) {
+            this.method = method;
+            return this;
+        }
+
         /**
          * @param processor The payment processor used for the transaction.
          * @return The builder object.
@@ -64,6 +76,14 @@ public Payment build() {
         }
     }
 
+    /**
+     * @return The payment method.
+     */
+    @JsonProperty("method")
+    public Method getMethod() {
+        return method;
+    }
+
     /**
      * @return The payment processor.
      */
@@ -262,4 +282,57 @@ public String toString() {
             return this.name().toLowerCase();
         }
     }
+
+    /**
+     * Enumeration of payment methods
+     */
+    public enum Method {
+        /**
+         * Bank debit payment
+         */
+        BANK_DEBIT,
+        /**
+         * Bank redirect payment
+         */
+        BANK_REDIRECT,
+        /**
+         * Bank transfer payment
+         */
+        BANK_TRANSFER,
+        /**
+         * Buy now, pay later payment
+         */
+        BUY_NOW_PAY_LATER,
+        /**
+         * Card payment
+         */
+        CARD,
+        /**
+         * Cryptocurrency payment
+         */
+        CRYPTO,
+        /**
+         * Digital wallet payment
+         */
+        DIGITAL_WALLET,
+        /**
+         * Gift card payment
+         */
+        GIFT_CARD,
+        /**
+         * Real time payment
+         */
+        REAL_TIME_PAYMENT,
+        /**
+         * Rewards payment
+         */
+        REWARDS;
+
+        /**
+         * @return a string representation of the object.
+         */
+        public String toString() {
+            return this.name().toLowerCase();
+        }
+    }
 }

src/test/java/com/maxmind/minfraud/request/PaymentTest.java

@@ -4,11 +4,24 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.maxmind.minfraud.request.Payment.Builder;
+import com.maxmind.minfraud.request.Payment.Method;
 import com.maxmind.minfraud.request.Payment.Processor;
 import org.junit.jupiter.api.Test;
 
 public class PaymentTest {
 
+    @Test
+    public void testMethod() {
+        Payment payment = new Builder().method(Method.CARD).build();
+        assertEquals(Method.CARD, payment.getMethod());
+
+        payment = new Builder().method(Method.DIGITAL_WALLET).build();
+        assertEquals(Method.DIGITAL_WALLET, payment.getMethod());
+
+        payment = new Builder().method(Method.BUY_NOW_PAY_LATER).build();
+        assertEquals(Method.BUY_NOW_PAY_LATER, payment.getMethod());
+    }
+
     @Test
     public void testProcessor() {
         Payment payment = new Builder().processor(Processor.ADYEN).build();