Container colspan not working

[tgrigoryan234]

\TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\B13\Container\Tca\Registry::class)->configureContainer(
    (
    new \B13\Container\Tca\ContainerConfiguration(
        'b13-2cols-with-header-container', // CType
        '2 Column Container With Header', // label
        'Some Description of the Container', // description
        [
            [
                ['name' => 'header', 'colPos' => 200, 'colspan' => 2, 'allowed' => ['CType' => 'header, textmedia']]
            ],
            [
                ['name' => 'left side', 'colPos' => 201],
                ['name' => 'right side', 'colPos' => 202]
            ]
        ] // grid configuration
    )
    )
        // set an optional icon configuration
        ->setIcon('EXT:container_example/Resources/Public/Icons/b13-2cols-with-header-container.svg')
);

I added containers according to the documentation and realised that COLSPAN does not work.

[chesio]

Hey @tgrigoryan234, have a look at #505 - perhaps it's the same issue?