testData.clear();
        testData.add(createRelatedContent("test", "Updated Content", ""));
        mockBhv.setTestData(testData);

        relatedContentHelper.update();
        // Give a moment for async execution
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            // ignore
        }

        results = relatedContentHelper.getRelatedContents("test");

    checkState(count() > 1);
    return sumOfProductsOfDeltas / (count() - 1);
  }

  /**
   * Returns the <a href="http://mathworld.wolfram.com/CorrelationCoefficient.html">Pearson's or
   * product-moment correlation coefficient</a> of the values. The count must greater than one, and
   * the {@code x} and {@code y} values must both have non-zero population variance (i.e. {@code

    logger.log(logLevel, message, t)
  }

  open fun isCleartextTrafficPermitted(hostname: String): Boolean = true

  /**
   * Returns an object that holds a stack trace created at the moment this method is executed. This
   * should be used specifically for [java.io.Closeable] objects and in conjunction with
   * [logCloseableLeak].
   */
  open fun getStackTraceForCloseable(closer: String): Any? =

        testData.clear();
        testData.add(createRelatedQuery("test", new String[] { "updated" }, ""));
        mockBhv.setTestData(testData);

        relatedQueryHelper.update();
        // Give a moment for async execution
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            // ignore
        }

        results = relatedQueryHelper.getRelatedQueries("test");

     * The value is, e.g. Fess <br>
     * comment: The title of the domain for logging and display.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getDomainTitle();

    /**
     * Get the value for the key 'search_engine.type'. <br>
     * The value is, e.g. default <br>
     * comment: The type of search engine backend (e.g., default, opensearch).

    public void test_reload_withEmptyLines() throws Exception {
        // Create content with empty lines and comments
        String content = "# Comment line\n" + "\n" + // empty line
                "word1\n" + "  \n" + // whitespace line (may be treated as content)
                "# Another comment\n" + "word2\n";

        // Write content to test file
        writeTestFile(content);

        // Reload and verify

     * The value is, e.g. warm <br>
     * comment: The mode of Lasta Di's smart-deploy, should be cool in production (e.g. hot, cool, warm)
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getLastaDiSmartDeployMode();

    /**
     * Get the value for the key 'development.here'. <br>
     * The value is, e.g. true <br>

    }

    // Test reload with InputStream
    public void test_reload_withComments() {
        String content = "# This is a comment\n" + "word1\n" + "\n" + // empty line
                "word2\n" + "# Another comment\n" + "word3\n";

        InputStream is = new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8));
        stopwordsFile.reload(null, is);

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

    final void copyIfNecessary() {
      if (forceCopy) {
        copy();
        forceCopy = false;
      }
    }

    void copy() {
      requireNonNull(impl); // see the comment on the field
      impl = impl.copy();
    }

    @Override

    }

    @Override
    public void storeToXML(final OutputStream os, final String comment, final String encoding) throws IOException {
        getProperties().storeToXML(os, comment, encoding);
    }

    @Override
    public void storeToXML(final OutputStream os, final String comment) throws IOException {
        getProperties().storeToXML(os, comment);
    }

    @Override
    public Set<String> stringPropertyNames() {