fix java client

java/plasma/src/main/java/org/apache/arrow/plasma/PlasmaClient.java

@@ -81,34 +81,11 @@ public class PlasmaClient implements ObjectStoreLink {
     return ret;
   }
 
-  @Override
-  public List<byte[]> wait(byte[][] objectIds, int timeoutMs, int numReturns) {
-    byte[][] readys = PlasmaClientJNI.wait(conn, objectIds, timeoutMs, numReturns);
-
-    List<byte[]> ret = new ArrayList<>();
-    for (byte[] ready : readys) {
-      for (byte[] id : objectIds) {
-        if (Arrays.equals(ready, id)) {
-          ret.add(id);
-          break;
-        }
-      }
-    }
-
-    assert (ret.size() == readys.length);
-    return ret;
-  }
-
   @Override
   public byte[] hash(byte[] objectId) {
     return PlasmaClientJNI.hash(conn, objectId);
   }
 
-  @Override
-  public void fetch(byte[][] objectIds) {
-    PlasmaClientJNI.fetch(conn, objectIds);
-  }
-
   @Override
   public List<ObjectStoreData> get(byte[][] objectIds, int timeoutMs) {
     ByteBuffer[][] bufs = PlasmaClientJNI.get(conn, objectIds, timeoutMs);