public void GetItem_Int_Test()
{
// Arrange
var dic = new StringKeyDictionary <int?>(new Dictionary <string, int?>()
{
{ "null", null }, { "ok", 123 }
});
// Act & assert
Assert.IsNull(dic.GetItem("null"));
Assert.IsNotNull(dic.GetItem("ok"));
var key = dic.GetItem("key");
Assert.IsNull(key);
}