Property type closed choice

[Allison, Timothy B.]

In working on Tika-1294, I thought that I'd try adding the following to 
TikaCoreProperties:

public static final Property EMBEDDED_RESOURCE_TYPE = 
          Property.internalClosedChoise("embedded_resource_type", 
                new String[]{"attachment", "inline"});

When I run this:
       Property attach = TikaCoreProperties.EMBEDDED_RESOURCE_TYPE;
       Metadata m = new Metadata();
       m.add(attach, "blah");       
       m.set(attach, "blah");

I don't get an exception.  Should metadata be throwing an exception when a user 
tries to set a value that isn't in the closed set?  Or, am I misunderstanding 
the purpose of closed choice?

Thank you.

        Best,

               Tim