public static TouchstoneWriterCore Create(TouchstoneWriter parent)
 {
     return(parent.Keywords.Version switch
     {
         FileVersion.One => new TouchstoneWriterCoreV1(parent),
         FileVersion.Two => new TouchstoneWriterCoreV2(parent),
         _ => throw new NotImplementedException(),
     });
 protected TouchstoneWriterCore(TouchstoneWriter parent) => tsWriter = parent;