The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see
    https://groups.google.com/g/google-web-toolkit-contributors/c/CqYH59Dt_rQ/m/uVGW1QdUsXUJ
    for details.

    The summary is that it ignores one file in favor of the other.
    util.concurrent, like nearly all our packages, has two .gwt.xml files: one

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components>
	<include path="convention.xml" />
	<include path="lastaflute_core.xml"/>
	<include path="fess.xml" />

	<include path="crawler_opensearch.xml" />
	<include path="fess_thumbnail.xml"/>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components>
	<include path="convention.xml" />
	<include path="lastaflute_core.xml"/>
	<include path="fess.xml" />

	<include path="crawler_opensearch.xml" />
	<include path="fess_thumbnail.xml" />
	<include path="fess_ingest.xml" />

<?xml version="1.0" encoding="UTF-8"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components namespace="fessCrawler">
	<include path="crawler/container.xml" />
	<include path="crawler/robotstxt.xml" />
	<include path="crawler/contentlength.xml" />
	<include path="crawler/mimetype.xml" />

	<component name="internalHttpClient" class="org.codelibs.fess.crawler.client.http.HcHttpClient"

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
	"http://dbflute.org/meta/lastadi10.dtd">
<components>
	<include path="esclient.xml"/>

	<!-- The components of DBFlute Runtime. -->
	<component name="invokerAssistant" class="org.codelibs.fess.opensearch.common.ImplementedInvokerAssistant"/>
	<component name="behaviorCommandInvoker" class="org.dbflute.bhv.core.BehaviorCommandInvoker"/>

<?xml version="1.0"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>org.codelibs</groupId>
	<artifactId>corelib</artifactId>
	<packaging>jar</packaging>
	<name>CodeLibs Core Library</name>
	<version>0.7.1-SNAPSHOT</version>

 * governing permissions and limitations under the License.
-->
<web-app xmlns="https://jakarta.ee/xml/ns/jakartaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee
                             web-app_6_0.xsd"
         version="6.0">

						</goals>
					</execution>
				</executions>
				<configuration>
					<addDefaultLicenseMatchers>true</addDefaultLicenseMatchers>
					<excludes>
						<exclude>pom.xml</exclude>
						<exclude>breaking-changes.xml</exclude>
						<exclude>*.md</exclude>
						<exclude>*.sh</exclude>
						<exclude>build.properties</exclude>
						<exclude>docs/**</exclude>
						<exclude>src/test/resources/**</exclude>

<?xml version="1.0" encoding="UTF-8"?>
<!--
  Licensed to the Apache Software Foundation (ASF) under one
  or more contributor license agreements. See the NOTICE file
  distributed with this work for additional information
  regarding copyright ownership. The ASF licenses this file
  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
  with the License. You may obtain a copy of the License at