When I serialize a an object with object fields that are nil  I get null values in the Json result e.g.     { "capabilities": { "positionEncoding": [], "textDocumentSync": { "openClose": true, "change": 2, "willSave": false, "willSaveWaitUntil": false, "save": null }, "notebookDocumentSync": null, "completionProvider": null, }   How can I ignore fields that have nil values?
System.JSON.Types defines the following:   TJsonDefaultValueHandling = (Include, Ignore, Populate, IgnoreAndPopulate); but it is not used anywhere.   I also tried to use a converter, but I could not get it to work.  And in any case converters are used after the property name is written.   Any ideas?