attribute::getStyleClasses

static function getStyleClasses(string $content): array
{
	if (preg_match_all('/class="([^"]+)"/', $content, $matches))
	{
		$allClasses = [];
		foreach ($matches[1] as $classes)
		{
			// some hack for future search optimization
			$allClasses[] = ' ' . $classes . ' ';
		}
		return $allClasses;
	}
	return [];
}