Using reflections to test doInBackground() method in asyncTask

The method signature of the doInBackground method in AsyncTask.class looks like this:

protected Boolean doInBackground(MyObject... params);

And inside the test with reflection it looks like this:

try {
Method doInBackgroundMethod = asyncTaskInstance.getClass().getDeclaredMethod("doInBackground", MyObject[].class);
            doInBackgroundMethod.setAccessible(true);
            boolean success = (boolean) doInBackgroundMethod.invoke(asyncTaskInstance, myObjectInstance);
            Assert.assertTrue(success);
} catch ...

but I get the following error:

java.lang.IllegalArgumentException: argument type mismatch, on line "doInBackgroundMethod.invoke(asyncTaskInstance, myObjectInstance);"

Do you have any idea how to solve this problem?