if (!source.isEmpty()) {
          return false;
        }
      }
      return true;
    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }

        final ChatSource source = new ChatSource();

        assertNull(source.getUrl());
        assertNull(source.getTitle());
        assertNull(source.getSnippet());

        source.setUrl("https://example.com");
        source.setTitle("Example Page");
        source.setSnippet("This is a snippet...");

        assertEquals("https://example.com", source.getUrl());

        final Map<String, Object> source1 = new LinkedHashMap<>();
        source1.put("url", "https://example.com/page.html");
        source1.put("title", "First");
        source1.put("content", "First content");

        final Map<String, Object> source2 = new LinkedHashMap<>();
        source2.put("url", "https://example.com/page.html");
        source2.put("title", "Second");

        String type1 = event.getEventType();
        String type2 = event.getEventType();
        assertEquals(type1, type2);

        Map<String, Object> source1 = event.toSource();
        Map<String, Object> source2 = event.toSource();
        assertSame(source1, source2);
    }

    // Test edge cases for version numbers
    @Test
    public void test_versionNumberEdgeCases() {

    }

    /**
     * Adds a source to the message.
     *
     * @param source the source to add
     */
    public void addSource(final ChatSource source) {
        if (sources == null) {
            sources = new ArrayList<>();
        }
        sources.add(source);
    }

    /**
     * Checks if this is a user message.
     *
     * @return true if this is a user message

                <delete dir="${project.build.directory}/guava-gwt-sources" quiet="true" />
                <delete dir="${project.build.directory}/guava-test-gwt-sources" quiet="true" />

                <copy toDir="${project.build.directory}/guava-gwt-sources">
                  <fileset dir="${project.build.directory}/guava-sources">
                    <contains text="@GwtCompatible"/>
                  </fileset>

							<directory>${packaging.fess.lib.dir}/classes</directory>
							<sources>
								<source>
									<location>${project.build.directory}/tomcat-lib</location>
								</source>
							</sources>
						</mapping>
						<mapping>
							<directory>${packaging.fess.lib.dir}/classes/org/codelibs/fess</directory>
							<sources>
								<source>

    }

    /**
     * Add sources to a message (card style)
     */
    function addSourcesToMessage(messageElement, sources) {
        var html = '<div class="message-sources"><h6>' + escapeHtml(config.labels.sources) + '</h6><ul class="source-list">';

        for (var i = 0; i < sources.length; i++) {
            var source = sources[i];
            var title = source.title || source.url || ('Source ' + (i + 1));

        source.setTitle("Document Title");
        source.setUrl("https://test.com");
        source.setDocId("id-456");
        source.setSnippet("A short snippet");

        assertEquals(10, source.getIndex());
        assertEquals("Document Title", source.getTitle());
        assertEquals("https://test.com", source.getUrl());
        assertEquals("id-456", source.getDocId());
        assertEquals("A short snippet", source.getSnippet());

            },
            block = block
        )

    /**
     * Runs the binary compatibility check against two source trees.
     *
     * The fixture build supports both Java and Kotlin sources.
     *
     * @param v1 sources producer for V1, receiver is the `src/main` directory
     * @param v2 sources producer for V2, receiver is the `src/main` directory
     * @param block convenience block invoked on the result