*
     * @param key the key under which to store the session data, must not be {@code null}
     * @param oldValue the expected data currently associated with the key, may be {@code null}
     * @param newValue the data to associate with the key, may be {@code null} to remove the mapping
     * @return {@code true} if the key mapping was successfully updated from the old value to the new value,

                data.set(key, value);
            }

            @Override
            public <T> boolean replace(@Nonnull Key<T> key, @Nullable T oldValue, @Nullable T newValue) {
                return data.set(key, oldValue, newValue);
            }

            @Nullable
            @Override
            @SuppressWarnings("unchecked")
            public <T> T get(@Nonnull Key<T> key) {