return OptionalEntity.empty();
            }
        }, WebConfigService.class.getCanonicalName());

        assertTrue(crawlingConfigHelper.getPipeline("W1").isEmpty());
    }

    public void test_getPipeline_withEmptyStringPipeline() {
        // Register service that returns empty string pipeline
        ComponentUtil.register(new WebConfigService() {

}

// Use a Scanner with a custom split function to parse a comma-separated
// list with an empty final value.
func ExampleScanner_emptyFinalToken() {
	// Comma-separated list; last entry is empty.
	const input = "1,2,3,4,"
	scanner := bufio.NewScanner(strings.NewReader(input))
	// Define a split function that separates on commas.

   *
   * <p>If you only want to calculate the mean, use {@link #meanOf} instead of creating a {@link
   * Stats} instance.
   *
   * @throws IllegalStateException if the dataset is empty
   */
  public double mean() {
    checkState(count != 0);
    return mean;
  }

  /**
   * Returns the sum of the values.
   *
   * <h3>Non-finite values</h3>
   *

  /**
   * Trailers received when the response body became exhausted.
   *
   * If the response body was successfully read until the end, this is the headers that followed,
   * or empty headers if there were none that followed.
   *
   * If the response body was closed prematurely or failed with an error, this will be the sentinel

      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }

  /**
   * Reads all the lines of this source as a list of strings. The returned list will be empty if
   * this source is empty.
   *
   * <p>Like {@link BufferedReader#readLine()}, this method considers a line to be a sequence of
   * text that is terminated by (but does not include) one of {@code \r\n}, {@code \r} or {@code

      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }

  /**
   * Reads all the lines of this source as a list of strings. The returned list will be empty if
   * this source is empty.
   *
   * <p>Like {@link BufferedReader#readLine()}, this method considers a line to be a sequence of
   * text that is terminated by (but does not include) one of {@code \r\n}, {@code \r} or {@code

                logger.debug("Failed to parse a value of {}.", name, e);
            }
        }
        return OptionalObject.empty();
    }

    @Override
    public OptionalThing<Locale> getRequestedLocale(final RequestManager requestManager) {
        return OptionalObject.empty(); // means browser default
    }

    // ===================================================================================

  /**
   * Returns the minimal range {@linkplain Range#encloses(Range) enclosing} the ranges in this
   * {@code RangeMap}.
   *
   * @throws NoSuchElementException if this range map is empty
   */
  Range<K> span();

  /**
   * Maps a range to a specified value (optional operation).
   *
   * <p>Specifically, after a call to {@code put(range, value)}, if {@link

                    postcard.setCrawlerExecTime(getValueFromMap(dataMap, "crawlerExecTime", "0"));
                    postcard.setCrawlerStartTime(getValueFromMap(dataMap, "crawlerStartTime", StringUtil.EMPTY));
                    postcard.setDataCrawlEndTime(getValueFromMap(dataMap, "dataCrawlEndTime", StringUtil.EMPTY));

     *
     * @param algorithm
     *            The algorithm (refer to the Javadoc of {@link MessageDigest} for available algorithms).
     *            Must not be {@literal null} or an empty string.
     * @return {@link MessageDigest}
     * @throws RuntimeException
     *             If a {@link NoSuchAlgorithmException} occurs
     */
    public static MessageDigest getInstance(final String algorithm) {