C# .NET - How to pass parameters to IEnumerable

I have a class

 [DataContract(Name = "SearchRequestArgs", Namespace = "")]
    public class SearchRequestArgs
    {
      [DataMember(Name = "UserType", Order = 1)]
      public Actor UserType { get; set; }
      [DataMember(Name = "SearchCriteria", Order = 2)]
      public IEnumerable<KeyValuePair<string,string>> SearchCriteria  { get; set; }
    }

So I have to pass data from unit test class

  
so for SearchCriteria I pass static data?

Please give me an example?