laravel5/vendor/phar-io/manifest/tests/_fixture/extension.xml

<?xml version="1.0" encoding="UTF-8"?>
<phar xmlns="https://phar.io/xml/manifest/1.0">
    <contains name="phpunit/phpunit-example-extension" version="1.0.0" type="extension">
        <extension for="phpunit/phpunit" compatible="^5.7"/>
    </contains>
    <copyright>
        <author name="Sebastian Bergmann" email="sebastian@phpunit.de"/>
        <license type="BSD-3-Clause" url="https://github.com/sebastianbergmann/phpunit-example-extension/blob/master/LICENSE"/>
    </copyright>
    <requires>
        <php version="^7.0"/>
    </requires>
</phar>