title: OData V4 (webapi) patch with NavigationProperty collection breaks deserailization on server
body: <p>I’m trying to go against a Web API Patch method that accepts a Delta. My entity has a navigational property that is a collection. The domain model is trivial, I have a team (entity) and a collection of members (navigational property).</p>
  
  <p>I’m using HttpClient directly instead of the OData client. </p>
  
  <p>The problem I’m running into is that when I send a patch request with the payload = a Team, the Delta deserialized in my controller is null when I include the navigational property collection in my payload.</p>
  
  <p>Eg (ignore that the missing quotes, this is typed in}:</p>
  
  <p>{ Name: Foo } -> serializes to Delta successfully.
  {Name: Foo, Members : [] } -> fails to serialize and Delta is null.</p>
  
  <p>Is this supported? I could not find concrete documentation online about whether you can supply navigational properties as an entire collection on patch (not looking for merge support, just want full replace of the collection.)</p>
  
  <p>I also tried tweaking my client to directly send a Delta payload, but the default JsonMediaTypeFormatter is unable to serialize this into a valid request body (always produces empty Json), and the ODataMediaTypeFormatter throws an exception saying it cannot write an object of type Delta, although I have initialized it with every ODataPayloadKind.</p>
  
  <p>I’m sure I’m either doing something wrong or missing something basic, assuming using Delta + patch with HttpClient is not this challenging.</p>