// TODO: Deprecate changing roles of unlocked non-legacy configurations.

        assertCanAdd(name);
        validateNameIsAllowed(name);
        Configuration configuration = defaultConfigurationFactory.create(name, this, resolutionStrategyFactory, rootComponentMetadataBuilder, role);
        add(configuration);

        }
    }

    /**
     * Asserts that the given item can be added to this collection.
     */
    protected void assertCanAdd(T t) {
        assertCanAdd(getNamer().determineName(t));
    }

    @Override
    public Namer<T> getNamer() {
        return Cast.uncheckedNonnullCast(this.namer);
    }

    protected Instantiator getInstantiator() {
        return instantiator;
    }