Umbraco-CMS/src/Umbraco.PublishedCache.NuCache/DomainCacheExtensions.cs

using System.Linq;
using Umbraco.Cms.Core.PublishedCache;

namespace Umbraco.Cms.Infrastructure.PublishedCache
{
    public static class DomainCacheExtensions
    {
        public static bool GetAssignedWithCulture(this IDomainCache domainCache, string culture, int documentId, bool includeWildcards = false)
        {
            var assigned = domainCache.GetAssigned(documentId, includeWildcards);

            return culture is null ? assigned.Any() : assigned.Any(x => x.Culture == culture);
        }
    }
}