[html-formfu] Different attributes for the first record in a repeatable block

[Ascii King]

I apologize for asking this twice, but I have not yet solved it.
Is it possible to specify a different characteristic for the first 
record in a repeatable? I would like the class in the first repeatable 
block to be different from the rest of the class tags. Something like a 
first_record_attributes option or the header in a table.

   - type: Repeatable
    first_record_attributes:
       class: outer-ring
     attributes:
       class: inner-ring
     elements:

The above code would produce the desired output shown below. 
"outer-ring" and "inner-ring" are the only differences.

<div class="outer-ring">
    blah blah - first record
</div>

<div class="inner-ring">
    blah blah - second record
</div>

<div class="inner-ring">
    blah blah - third record
</div>