Fix failing test

Author: msimacek

graalpython/com.oracle.graal.python.test/src/com/oracle/graal/python/test/objects/PythonObjectLibraryTests.java

@@ -58,6 +58,7 @@
 import com.oracle.graal.python.builtins.objects.object.PythonObjectLibrary;
 import com.oracle.graal.python.runtime.object.PythonObjectFactory;
 import com.oracle.graal.python.test.PythonTests;
+import com.oracle.truffle.api.interop.TruffleObject;
 
 public class PythonObjectLibraryTests extends PythonTests {
 
@@ -83,8 +84,8 @@ public void testLookupAttribute() {
         lookupAttr(() -> 1, "__str__", false);
         lookupAttr(() -> (long) 1, "__str__", false);
         lookupAttr(() -> "abc", "__str__", false);
-
-        lookupAttr(() -> new Object(), "__str__", true);
+        lookupAttr(() -> new TruffleObject() {
+        }, "__str__", false);
 
         lookupAttr(() -> PythonObjectFactory.getUncached().createInt(1), "__str__", false);