[plt-scheme] "appending" to classes rather than extending

Hi all,

I'm looking to be able to append a few methods to a class.  In Ruby, I
can do something like this:

class Foo
  def bar
    ...
  end
  ...
end

class Foo
  def baz
    ...
  end
end

and both bar and baz will be a part of Foo (these two class defs could
be in the same file, or in two different files that are both loaded).
Anything like this in the PLT Scheme class system?

Thanks,
Rob