add fake proof test

bindings/java/src/test/java/CKZg4844JNITest.java

@@ -1,4 +1,5 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -35,6 +36,9 @@ public class CKZg4844JNITest {
 
     assertTrue(CKzg4844JNI.verifyAggregateKzgProof(blobs, commitments, 2, proof));
 
+    final byte[] fakeProof = createRandomProof();
+    assertFalse(CKzg4844JNI.verifyAggregateKzgProof(blobs, commitments, 2, fakeProof));
+
     CKzg4844JNI.freeTrustedSetup();
 
   }
@@ -100,6 +104,11 @@ public class CKZg4844JNITest {
     return blob;
   }
 
+  private byte[] createRandomProof() {
+    final byte[] blob = createRandomBlob();
+    return CKzg4844JNI.computeAggregateKzgProof(blob, 1);
+  }
+
   private byte[] flatten(byte[]... bytes) {
     final int capacity = Arrays.stream(bytes).mapToInt(b -> b.length).sum();
     final ByteBuffer buffer = ByteBuffer.allocate(capacity);