title: Sensenet length filter Not working
body: <p>I want to query the Field which are empty and which are not empty using Sensenet Odata Rest API. Their documentation mentions a filter function called 'length'. I have tried to query the field with the length operation but it fails with the error.</p>
  
  <p>This is the filter I have used</p>
  
  <pre><code>$filter=length(Name) eq 2
  </code></pre>
  
  <p>Sense/Net 6.5.4.9496</p>
  
  <p>Exception </p>
  
  <pre><code>"code": "NotSpecified",
  "exceptiontype": "SnNotSupportedException",
  "message": {
  "lang": "en-us",
  "value": "Unknown method: length"
  },
  </code></pre>
  
  <p>Wiki Link <a href="http://wiki.sensenet.com/OData_REST_API" rel="nofollow">http://wiki.sensenet.com/OData_REST_API</a></p>