FIX: Call correct method for overloaded asyncBopUpsert method

src/main/java/net/spy/memcached/ArcusClient.java

@@ -1917,7 +1917,7 @@ public void gotTrimmedKey(String key, Object bkey) {
   public CollectionFuture<Boolean> asyncBopUpsert(String key, long bkey,
                                                   byte[] elementFlag, Object value,
                                                   CollectionAttributes attributesForCreate) {
-    return asyncBopInsert(key, bkey, elementFlag, value, attributesForCreate, collectionTranscoder);
+    return asyncBopUpsert(key, bkey, elementFlag, value, attributesForCreate, collectionTranscoder);
   }
 
   @Override

src/test/manual/net/spy/memcached/collection/btree/BopUpsertTest.java

@@ -16,13 +16,18 @@
  */
 package net.spy.memcached.collection.btree;
 
+import java.util.Map;
+
 import net.spy.memcached.collection.BaseIntegrationTest;
 import net.spy.memcached.collection.CollectionAttributes;
+import net.spy.memcached.collection.Element;
+import net.spy.memcached.internal.CollectionFuture;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
@@ -58,4 +63,25 @@ void testUpsertNotExistsKey() {
       fail(e.getMessage());
     }
   }
+
+  @Test
+  void upsertExistingElement() throws Exception {
+    // given
+    CollectionFuture<Boolean> future
+            = mc.asyncBopUpsert(KEY, BKEY, null, "INITIAL_VALUE", new CollectionAttributes());
+    boolean result = future.get();
+    assertTrue(result);
+
+    // when
+    future = mc.asyncBopUpsert(KEY, BKEY, null, "UPDATED_VALUE", null);
+    result = future.get();
+
+    // then
+    assertTrue(result);
+    CollectionFuture<Map<Long, Element<Object>>> futureToGet
+            = mc.asyncBopGet(KEY, BKEY, null, false, false);
+    Map<Long, Element<Object>> elements = futureToGet.get();
+    assertTrue(elements.containsKey(BKEY));
+    assertEquals("UPDATED_VALUE", elements.get(BKEY).getValue());
+  }
 }