returns xml fragment.
<response success="true" error="">
if success attribute is "true", the folders have been returned successfully like the sample below.
if success attribute is "false", the error attribute indicates the encountered error.
<response success="true" error="" folderid="1000" parentid="0" name="Corporate" path="\Corporate" folderfilter="" page="1" pageSize="20" itemcount="5">
<f id="1011" n="Abc Corp."/>
<f id="1017" n="Noises"/>
<f id="1016" n="Mac"/>
<f id="1018" n="My Definitions"/>
<f id="1010" n="Testing"/>
</response>