I try to work with Guava's `ClassToInstanceMap<MyObject>`.

I want to have my clients to use a method `addMyObject(MyObject)`, so I tried to write these methods:

```
private final ClassToInstanceMap<MyObject> instances = MutableClassToInstanceMap.create();

public void addMyObject1(MyObject o) {
    instances.putInstance(o.getClass(), o);
}

public <O extends MyObject> void addMyObject2(O o) {
    instances.putInstance(o.getClass(), o);
}

```

But naturally, none of these two methods compile.

So, how to use this properly?