@BeforeEach
    @SuppressWarnings("unchecked")
    public void setup() {
        chains = new LinkedHashMap<>();

        key1a = Key.get(Filter.class, Names.named("key1a"));
        key1b = Key.get(Filter.class, Names.named("key1b"));
        key1c = Key.get(Filter.class, Names.named("key1c"));
        key2a = Key.get(Filter.class, Names.named("key2a"));

        chains.put("one", new Key[] {key1a, key1b, key1c});
        chains.put("two", new Key[] {key2a});

        underTest = new FilterChainResolverProvider(chains);
    }
This test relies on the internal structure of FilterChainResolver in order to check that it got created correctly.
support/guice/src/test/java/org/apache/shiro/guice/web/FilterChainResolverProviderTest.java