What is happening here?

I'm confused about the second object that is created. The loadedObject is the same as the classWithStatic as we read from the file. But what is happening to the new values? It seems that it is completely ignored. Now I tried to write to objects to the file by trying loadedObject.save(outputStream) but then CodeGym gives me an error that there is something wrong with my load/save method. I'm confused why I can't write several objects to the outputSTream. Where do I go wrong in my thinking?

//writing to the file
            ClassWithStatic classWithStatic = new ClassWithStatic();
            classWithStatic.i = 3;
            classWithStatic.j = 4;
            classWithStatic.save(outputStream);
            outputStream.flush();

            //reading from the file
            ClassWithStatic loadedObject = new ClassWithStatic();
            loadedObject.staticString = "something";
            loadedObject.i = 6;
            loadedObject.j = 7;
loadedObject.save(outputStream);