/// <summary>
 /// Get assets of the group.
 /// </summary>
 /// <typeparam name="TContentMedia">Type of media.</typeparam>
 /// <param name="assetContainer">Asset container.</param>
 /// <param name="groupName">Asset group name.</param>
 /// <returns>The list of found assets URLs.</returns>
 public static IList <string> GetAssets <TContentMedia>(this IAssetContainer assetContainer, string groupName)
     where TContentMedia : IContentMedia
 {
     if (groupName == null)
     {
         throw new ArgumentNullException(nameof(groupName));
     }
     return(assetContainer.GetAssets <TContentMedia>(new[] { groupName }));
 }
 /// <summary>
 /// Get assets of Episerver's default group.
 /// </summary>
 /// <typeparam name="TContentMedia">Type of media.</typeparam>
 /// <param name="assetContainer">Asset container.</param>
 /// <returns>The list of found assets URLs.</returns>
 public static IList <string> GetDefaultAssets <TContentMedia>(this IAssetContainer assetContainer)
     where TContentMedia : IContentMedia
 {
     return(assetContainer.GetAssets <TContentMedia>(new[] { EpiserversDefaultGroupName }));
 }
 /// <summary>
 /// Get the first asset of the group.
 /// </summary>
 /// <typeparam name="TContentMedia">Type of media.</typeparam>
 /// <param name="assetContainer">Asset container.</param>
 /// <param name="groupName">Asset group name.</param>
 /// <returns>Url of the found asset or empty string if asset not found.</returns>
 public static string GetAsset <TContentMedia>(this IAssetContainer assetContainer, string groupName)
     where TContentMedia : IContentMedia
 {
     return(assetContainer.GetAssets <TContentMedia>(groupName).FirstOrDefault() ?? string.Empty);
 }
 /// <summary>
 /// Get all assets.
 /// </summary>
 /// <typeparam name="TContentMedia">Type of media.</typeparam>
 /// <param name="assetContainer">Asset container.</param>
 /// <returns>The list of found assets URLs.</returns>
 public static IList <string> GetAssets <TContentMedia>(this IAssetContainer assetContainer)
     where TContentMedia : IContentMedia
 {
     return(assetContainer.GetAssets <TContentMedia>(new string[0]));
 }