setUpBeforeClass not called when slice activated

[SimoneDoc]

If you exec slicer without slices options it works well
vendor/bin/phpunit-slicer --color --configuration configuration.xml

If you use the slices options, the setUpBeforeClass hook was not called and test fails
vendor/bin/phpunit-slicer --color --configuration configuration.xml --slices 1/1

php-slicer 1.0
phpunit/phpunit 7.5.20

TestDummy.php

<?php

use PHPUnit\Framework\TestCase;

class TestDummy extends TestCase
{
    static $called = false;

    public static function setUpBeforeClass()
    {
        parent::setUpBeforeClass();
        self::$called = true;
    }

    public function testSetUpBeforeClassIsCalled()
    {
        $this->assertTrue(self::$called);
    }
}

Configurations.xml

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

<phpunit>

    <testsuites>

        <testsuite name="testsuite-dummy">
            <directory>TestDummy.php</directory>
        </testsuite>

    </testsuites>


</phpunit>