In the <response> tag in the XML, is we have a structure:

  <response>
    <foo>
      <bar>1</bar>
      <bar>2</bar>
    </foo>
    <foo>
      <wallaby id="9.5"><fred /></wallaby>
    </foo>
  </response>

there's no sanity checking done to ensure that both 'foo' tags look
the same - what are they _supposed_ to look like?

