WebDAV request-response examples? Especially PROPFIND - webdav

Question

I'm currently implementing a WebDAV server and am totally stuck at the PROPFIND method handling. Are there any resources out there with actual examples? I have a hard time following the specification, which is imo very vague. Here's e.g. a request "Litmus" sends my server:
<?xml version="1.0" encoding="UTF-8"?>
<a:propfind xmlns:a="DAV:" xmlns="DAV:">
<b:prop xmlns:b="DAV:">
<b:getcontentlength/>
<b:getlastmodified/>
<b:displayname/>
<b:resourcetype/>
<c:foo xmlns:c="http://example.com/neon/litmus/" xmlns="http://example.com/neon/litmus/"/>
<bar/>
</b:prop>
</a:propfind>
Apparently, my response to that is not okay, since Litmus says "4. propfind_d0........... FAIL (No responses returned)":
<?xml version="1.0" encoding="UTF-8"?>
<DAV:multistatus
xmlns:DAV="DAV:">
<DAV:response>
<DAV:href>/test/litmus/</DAV:href>
<DAV:propstat>
<DAV:prop>
<DAV:getlastmodified>Fri, 30 Sep 2016 23:28:31 +0000</DAV:getlastmodified>
<DAV:displayname>litmus</DAV:displayname>
<DAV:resourcetype>
<DAV:collection></DAV:collection>
</DAV:resourcetype>
</DAV:prop>
<DAV:status>HTTP/1.1 200 OK</DAV:status>
</DAV:propstat>
<DAV:propstat>
<DAV:prop>
<DAV:getcontentlength></DAV:getcontentlength>
<a:foo
xmlns:a="http://example.com/neon/litmus/">
</a:foo>
<a:bar></a:bar>
</DAV:prop>
<DAV:status>HTTP/1.1 404 Not Found</DAV:status>
</DAV:propstat>
</DAV:response>
</DAV:multistatus>
What would be a correct response, and how can I actually find out?