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?