Path getTopDirectory();

    /**
     * Gets the root directory of the session, which is the root directory for the top directory project.
     *
     * @return the root directory, never {@code null}
     * @throws IllegalStateException if the root directory could not be found
     * @see #getTopDirectory()
     * @see Project#getRootDirectory()
     * @see Project#isRootProject()
     */
    @Nonnull
    Path getRootDirectory();

        if (configId == null) {
            throw new FessSystemException("configId is null.");
        }
        if (configId.length() < 2) {
            throw new FessSystemException("Invalid configId: " + configId);
        }
        final CrawlingConfig config = crawlingConfigHelper.getCrawlingConfig(configId);
        if (config == null) {
            throw new FessSystemException("No crawlingConfig: " + configId);

     * @return complete URL with context path and optional timestamp parameter
     * @throws IllegalArgumentException if input is null or doesn't start with '/'
     */
    public static String url(final String input) {
        if (input == null) {
            final String msg = "The argument 'input' should not be null.";
            throw new IllegalArgumentException(msg);
        }
        if (!input.startsWith("/")) {

   *
   * @return a new, empty map instance.
   * @throws UnsupportedOperationException if it's not possible to make an empty instance of the
   *     class under test.
   */
  protected abstract Map<K, V> makeEmptyMap() throws UnsupportedOperationException;

  /**
   * Creates a new, non-empty instance of the class under test.
   *
   * @return a new, non-empty map instance.

     *
     * It is an error to call this multiple times on the same instance.
     *
     * @throws IllegalStateException if this request doesn't have a request body, or if it already
     *     has a 'Content-Encoding' header.
     */
    fun gzip() =
      apply {
        val identityBody =
          body
            ?: throw IllegalStateException("cannot gzip a request that has no body")

                this.exception = e;
            }

            @Override
            public int decode(byte[] buffer, int bufferIndex) throws SMBProtocolDecodingException {
                if (buffer == null || buffer.length < bufferIndex + 4) {
                    throw new SMBProtocolDecodingException("Buffer too small");
                }
                return 4;
            }

            @Override

   * @throws NullPointerException if both {@code first} and {@code second} are null
   * @since 18.0 (since 3.0 as {@code Objects.firstNonNull()}).
   */
  public static <T> T firstNonNull(@Nullable T first, @Nullable T second) {
    if (first != null) {
      return first;
    }
    if (second != null) {
      return second;
    }
    throw new NullPointerException("Both parameters are null");

    }

    // Uses reflection to set internal array to null to exercise defensive branch in length()
    @Test
    @DisplayName("length(): handles internal null defensively")
    void length_handlesNullInternalArray() throws Exception {
        // Arrange
        SecurityBlob blob = new SecurityBlob(new byte[] { 1, 2, 3 });

        // Force internal field to null via reflection to exercise defensive branch

   * for {@code asMapOfRanges().iterator().remove()}.
   *
   * <p>The returned range map will throw an {@link IllegalArgumentException} on an attempt to
   * insert a range not {@linkplain Range#encloses(Range) enclosed} by {@code range}.
   */
  // TODO(cpovirk): Consider documenting that IAE on the various methods that can throw it.
  RangeMap<K, V> subRangeMap(Range<K> range);

  /**

    /**
     * Returns a media type for this string.
     *
     * @throws IllegalArgumentException if this is not a well-formed media type.
     */
    @JvmStatic
    @JvmName("get")
    fun String.toMediaType(): MediaType {
      val typeSubtype =
        TYPE_SUBTYPE.matchAt(this, 0)
          ?: throw IllegalArgumentException("No subtype found for: \"$this\"")