var id = currentPage.ContentLink.ID;
var parent = new ContentReference(id);

IContentRepository contentRepository =
EPiServer.ServiceLocation.ServiceLocator.Current.GetInstance<IContentRepository>();

var startpageLanguageBranch =
contentRepository.CreateLanguageBranch<HeaderBackgroundPage>(parent,
new LanguageSelector("sv"));

startpageLanguageBranch.PageName = "Start page test uk";
startpageLanguageBranch.Title = "Start page test uk";
startpageLanguageBranch.BackgroundImage = currentPage.BackgroundImage;

contentRepository.Save(startpageLanguageBranch,
EPiServer.DataAccess.SaveAction.Publish,
AccessLevel.NoAccess);

var xyz = startpageLanguageBranch.HeaderBlock;
foreach (var element in xyz.Items)
{
var b = element.ContentLink.ID;
var tobecopied = new ContentReference(b);

var startpagelanguagebranch1 =
contentRepository.CreateLanguageBranch<HeaderBlock>(tobecopied, new LanguageSelector("sv"));

contentRepository.Save(startpagelanguagebranch1, EPiServer.DataAccess.SaveAction.Publish, AccessLevel.NoAccess);
}
startpageLanguageBranch.HeaderBlock = currentPage.HeaderBlock;
startpageLanguageBranch.ContainerSize = currentPage.ContainerSize;

contentRepository.Save(startpageLanguageBranch,
EPiServer.DataAccess.SaveAction.Publish,
AccessLevel.NoAccess);