// Act & Assert
        assertThrows(NullPointerException.class, () -> handler.openConnection(null), "Null URL should throw NPE");
        verify(mockCtx, never()).getConfig(); // no interaction expected on failure before construction
    }

    @Test
    @DisplayName("openConnection uses SingletonContext when no context provided")
    void testOpenConnection_UsesSingletonContext() throws Exception {
        // Arrange

    MemoizingSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    @ParametricNullness
    // We set the field only once (during construction or deserialization).
    @SuppressWarnings("SynchronizeOnNonFinalField")
    public T get() {
      // A 2-field variant of Double Checked Locking.
      if (!initialized) {
        synchronized (lock) {

        // Assert
        assertNotNull(handle);
        verify(mockDcerpcHandle, times(1)).sendrecv(any(MsrpcLsarOpenPolicy2.class));
        // We cannot directly assert the 'opened' field as it's private, but successful construction implies it.
    }

    @Test
    void constructor_shouldHandleNullServerSuccessfully() throws IOException {
        // Arrange
        String server = null;
        int access = 123;

        AppConfigurationEntry[] entries = cfg.getAppConfigurationEntry("ignored");
        Map<String, ?> returned = entries[0].getOptions();

        // Assert: sanity check and verify that no mutating calls were made after construction
        assertEquals("true", returned.get("refreshKrb5Config"));
        verify(spyOpts, never()).put(any(), any());
        verify(spyOpts, never()).remove(any());
        verify(spyOpts, never()).clear();
    }

        when(mockConfig.getPid()).thenReturn(12345);
        response = new SmbComSeekResponse(mockConfig);
    }

    /* ------------------------------------------------------------------ */
    /* 1. Construction and basic getters                                    */
    /* ------------------------------------------------------------------ */

    @Test
    @DisplayName("Construct with a valid configuration - should not throw")

 *
 * <p><b>Warning:</b> {@code ArrayTable} is rarely the {@link Table} implementation you want. First,
 * it requires that the complete universe of rows and columns be specified at construction time.
 * Second, it is always backed by an array large enough to hold a value for every possible
 * combination of row and column keys. (This is rarely optimal unless the table is extremely dense.)

        when(cfg.getMaximumBufferSize()).thenReturn(5);

        BufferCacheImpl impl = new BufferCacheImpl(cfg);

        // Verify interactions happen exactly once during construction
        verify(cfg, times(1)).getBufferCacheSize();
        verify(cfg, times(1)).getMaximumBufferSize();
        verifyNoMoreInteractions(cfg);

    }

    @Nested
    @DisplayName("Invalid constructor inputs")
    class InvalidInputs {
        @Test
        @DisplayName("Null delegate causes NullPointerException during construction")
        void nullDelegate_throwsNPE() throws Exception {
            SmbFile parent = newParent();
            assertThrows(NullPointerException.class, () -> new ShareEnumIterator(parent, null, null));
        }

        when(this.mechContext.getFlags()).thenReturn(0x1234);
        when(this.mechContext.initSecContext(any(byte[].class), eq(0), eq(0))).thenReturn(new byte[] { 0x01, 0x02 });

        // Act: len==0 triggers initial token construction
        byte[] out = ctx.initSecContext(null, 0, 0);

        // Assert: returns a SPNEGO token (opaque here but non-null/non-empty)
        assertNotNull(out);
        assertTrue(out.length > 0);

     * Creates a new dictionary manager with an empty creator list.
     */
    public DictionaryManager() {
        // Default constructor
    }

    /**
     * Initializes the dictionary manager after construction.
     * Sets up the relationship between this manager and all registered creators.
     */
    @PostConstruct
    public void init() {
        if (logger.isDebugEnabled()) {