Using a metadata class to provide attributes to properties in another part of the same (partial) class

Metadata.cs

[MetadataType(typeof(PersonMetadata))]
public partial class Person
{
   public class PersonMetadata
   {
      [Required]
      public string Name { get; set; }
   }
}

// Elsewhere (and inaccessible)...
public partial class Person
{
   public string Name { get; set; }
}