/// <summary>
 /// Determines whether the content type varies by culture.
 /// </summary>
 public static bool VariesByCulture(this ISimpleContentType contentType) => contentType.Variations.VariesByCulture();
 /// <summary>
 /// Determines whether the content type varies by segment.
 /// </summary>
 public static bool VariesBySegment(this ISimpleContentType contentType) => contentType.Variations.VariesBySegment();
 /// <summary>
 /// Determines whether the content type is invariant.
 /// </summary>
 public static bool VariesByNothing(this ISimpleContentType contentType) => contentType.Variations.VariesByNothing();