src/test/resources/com/puppycrawl/tools/checkstyle/configurationloader/InputConfigurationLoaderMissingConfigName.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.1//EN"
    "http://checkstyle.sourceforge.net/dtds/configuration_1_1.dtd">

<module nam="Checker">
    <property name="tabWidth" value="4"/>
</module>