The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see https://goo.gl/pRV3Yn 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
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

        <module name="IllegalImport">
            <!--
                We shouldn't use jdk.internal types.
                
                com.beust and org.testng.collections has classes that look like Guava.

                We prefer to import javax.annotation and fully-qualify references to org.jetbrains.annotations.
            -->

            <property name="checkEmptyJavadoc" value="true"/>
        </module>

        <module name="JavadocType">
            <property name="scope" value="protected"/>
            <!-- Allow the use of unrecognized tags like @apiNote -->
            <property name="allowUnknownTags" value="true"/>
        </module>

        <!-- TODO - switch this on -->
        <!--<module name="JavadocMethod">-->

    <commonsCliVersion>1.0</commonsCliVersion>
    <!--

    Do not update this, Doxia will be decoupled completely from 3.x and someone can
    create a rendering engine for it if they like when the release stabilizes. JVZ

    -->
    <doxiaVersion>1.0-alpha-9</doxiaVersion>
    <easyMockVersion>1.2_Java1.3</easyMockVersion>
    <junitVersion>4.13.1</junitVersion>

  <offline>false</offline>
  -->

  <!-- pluginGroups
   | This is a list of additional group identifiers that will be searched when resolving plugins by their prefix, i.e.
   | when invoking a command line like "mvn prefix:goal". Maven will automatically add the group identifiers
   | "org.apache.maven.plugins" and "org.codehaus.mojo" if these are not already contained in the list.
   |-->
  <pluginGroups>
    <!-- pluginGroup

    The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see https://goo.gl/pRV3Yn 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
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

  |
  | o validators: there could be several levels of validation. Simple type validation could
  |   be done with a regex, but we need inter-field validation and rules which could be
  |   dealt with by something like drools.
  |
  | o i18n: would be good to be able to have names/descriptions/specifications
  |   in as many languages as possible. (see MNG-3626)
  |

    <commonsCliVersion>1.0</commonsCliVersion>
    <!--

    Do not update this, Doxia will be decoupled completely from 3.x and someone can
    create a rendering engine for it if they like when the release stabilizes. JVZ

    -->
    <doxiaVersion>1.0-alpha-9</doxiaVersion>
    <easyMockVersion>1.2_Java1.3</easyMockVersion>
    <junitVersion>4.13.1</junitVersion>

	<modelVersion>4.0.0</modelVersion>
	<groupId>org.codelibs</groupId>
	<artifactId>curl4j</artifactId>
	<version>1.2.9-SNAPSHOT</version>
	<packaging>jar</packaging>
	<name>cUrl-Like Java client</name>
	<inceptionYear>2011</inceptionYear>
	<licenses>
		<license>
			<name>The Apache Software License, Version 2.0</name>
			<url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>

              [INFO] Compile with -strict or with -logLevel set to TRACE or DEBUG to see all errors.

            Turning up the log level, we see that GWT is trying to compile classes from other
            packages, like RangeTest. The reason for this is that GWT doesn't distinguish between
            .java files in c.g.c.collect.Collect, a module that the c.g.c.base test module inherits,