Removing Null Properties from Json in MVC Web Api 4 Beta

In Json.Net you can use JsonPropertyAttribute with NullValueHandling=NullValueHandling.Ignore. Looks like here is no way to do this for whole class, only explicity for each class field/property.

[JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
public string SometimesNull { get; set; }

FYI. There is a reasons why Json.Net by default serialize properties with null values. Take a look, may be some of this reasons applicable to your cases.