Method to get generics type does not work

I am trying to get the type parameter of a List/Collection for my deserializer. I know I'm not the first asking and I saw in the answer this method to get the type parameter.

Class<?> persistentClass = (Class<?>) ((ParameterizedType) field.getType().getGenericSuperclass()).getActualTypeArguments()[0];

And it is not working form me. It is giving me a casting error saying that it cannot cast TypeVariableImpl to Class. And when I tried printing out the result it printed out just "E".

 else if (Collection.class.isAssignableFrom(field.getType())) {
            Collection collection = new ArrayList();

            JSONArray array = toDeserialize.optJSONArray(fieldName);
            if (array != null) {

                for (int i = 0; i < array.length(); i++) {
                    Object val = array.get(i);
                    Class<E> persistentClass = (Class<E>) ((ParameterizedType) field.getType().getGenericSuperclass()).getActualTypeArguments()[0];
                    if (ISerializable.class.isAssignableFrom(persistentClass)) {
                        collection.add(deserialize(((Class<ISerializable>) persistentClass), (JSONObject) val));
                    } else collection.add(val);
                }
            }

            try {
                field.set(object, collection);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }
}

This is the broken code.

I could I fix this?