impl = EmptySetBuilderImpl.instance();
      }
    }

    Builder(@SuppressWarnings("unused") boolean subclass) {
      this.impl = null; // unused
    }

    @VisibleForTesting
    void forceJdk() {
      requireNonNull(impl); // see the comment on the field
      this.impl = new JdkBackedSetBuilderImpl<>(impl);
    }

    final void copyIfNecessary() {
      if (forceCopy) {
        copy();

     * Share flag indicating that exclusive opens are restricted on this share.
     */
    public static final int SMB2_SHAREFLAG_RESTRICT_EXCLUSIVE_OPENS = 0x100;
    /**
     * Share flag indicating that shared delete is forced for this share.
     */
    public static final int SMB2_SHAREFLAG_FORCE_SHARED_DELETE = 0x200;
    /**
     * Share flag indicating that namespace caching is allowed on this share.
     */

      @Override
      public ImmutableBiMap<Object, Object> create(List<Entry<?, ?>> entries) {
        return ImmutableBiMap.builder().putAll(entries).buildOrThrow();
      }
    },
    FORCE_JDK {
      @Override
      public ImmutableBiMap<Object, Object> create(List<Entry<?, ?>> entries) {
        return ImmutableBiMap.builder().putAll(entries).buildJdkBacked();
      }
    };

    }

    @Test
    void acceptPropagatesException() {
        SmbFile dir = Mockito.mock(SmbFile.class);
        SmbFilenameFilter filter = (d, n) -> {
            throw new SmbException("forced exception");
        };
        Exception e = assertThrows(Exception.class, () -> filter.accept(dir, "any"));
        assertTrue(e instanceof SmbException);
    }

            assertEquals(transport, result);
            verify(transportPool).getSmbTransport(context, TEST_HOST, DEFAULT_PORT, true, false);
        }

        @Test
        @DisplayName("Should get transport by name with forced signing")
        void testGetSmbTransportByNameForceSigning() throws UnknownHostException, IOException {
            // Given

        // Arrange - mock cause to verify no interactions are needed to construct
        Throwable cause = Mockito.mock(Throwable.class);
        String message = "forced downgrade detected";

        // Act
        SMBProtocolDowngradeException ex = new SMBProtocolDowngradeException(message, cause);

        // Assert - fields preserved
        assertSame(cause, ex.getCause());

    throw new UnsupportedOperationException();
  }

  /**
   * {@inheritDoc}
   *
   * <p>This implementation of {@code getAllPresent} lacks any insight into the internal cache data
   * structure, and is thus forced to return the query keys instead of the cached keys. This is only
   * possible with an unsafe cast which requires {@code keys} to actually be of type {@code K}.
   *
   * @since 11.0
   */
  /*

   * return type is plain FilenameFilter. If we made such a change, then the annotation we choose
   * here would have no significance to end users, who would be forced to conform to the signature
   * used in FilenameFilter.)
   */
  @Override
  public boolean accept(File dir, String fileName) {
    return pattern.matcher(fileName).matches();
  }

    /**
     * Checks whether a connection can be reused for the given configuration.
     *
     * @param tc the CIFS context to check compatibility with
     * @param forceSigning whether signing is being forced
     * @return whether a connection can be reused for this config
     */
    boolean canReuse(CIFSContext tc, boolean forceSigning);

    throw new UnsupportedOperationException();
  }

  /**
   * {@inheritDoc}
   *
   * <p>This implementation of {@code getAllPresent} lacks any insight into the internal cache data
   * structure, and is thus forced to return the query keys instead of the cached keys. This is only
   * possible with an unsafe cast which requires {@code keys} to actually be of type {@code K}.
   *
   * @since 11.0
   */
  /*