Autoroute URL patterns containing custom tokens - orchardcms

Question

I'm having trouble getting my custom tokens to work with my ContentPart. My problem is the same as what is described here:
Is it possible to create an orchard autoroute using contents of a custom type property?
I have created my tokens:
namespace MyNS.Types.Providers
{
public class BioPartTokens : ITokenProvider
{
public BioPartTokens() {
T = NullLocalizer.Instance;
}
public Localizer T { get; set; }
public void Describe(dynamic context) {
context.For("Bio", T("Bio"), T("Tokens for the Bio content type"))
.Token("FirstName", T("FirstName"), T("First name of person."))
.Token("LastName", T("LastName"), T("Last name of person."));
}
public void Evaluate(dynamic context) {
context.For<BioPart>("Bio")
.Token("FirstName", (Func<BioPart, object>) (f => f.ContentItem.Parts.OfType<BioPart>().First().FirstName.ToLower()))
.Chain("FirstName", "FirstName", (Func<BioPart, object>)(f => f.ContentItem.Parts.OfType<BioPart>().First().FirstName.ToLower()))
.Token("LastName", (Func<BioPart, object>)(f => f.ContentItem.Parts.OfType<BioPart>().First().LastName.ToLower()))
.Chain("LastName", "LastName", (Func<BioPart, object>)(f => f.ContentItem.Parts.OfType<BioPart>().First().LastName.ToLower()))
;
}
}
}
My model:
namespace MyNS.Types.Models
{
public class BioPart: ContentPart<BioPartRecord>
{
public string FirstName {
get { return Record.FirstName; }
set { Record.FirstName = value; }
}
public string LastName
{
get { return Record.LastName; }
set { Record.LastName = value; }
}
public RoleInSchool RoleInSchool
{
get { return Record.RoleInSchool; }
set { Record.RoleInSchool = value; }
}
public bool IsBlogger {
get { return Record.IsBlogger; }
set { Record.IsBlogger = value; }
}
}
}
Though I've tried URL patterns with all of the following tokens, I've not been able to get a value back from the form that I've submitted:
{Content.Bio.FirstName}
{Content.BioPart.FirstName}
{Bio.FirstName}
{BioPart.FirstName}
No errors are being logged.