So im unit testing and I got the above message. Ive looked around and cannot find an answer to my problem. I have no idea what this means. Can there be two different kinds of Null? Thanks for the help!

//This is invalid input given to the CategoryList constructor. It returns a null value.    
//The message i get is: Assert.AreEqual failed. Expected:<Null>.Actual:<(null)>.

CategoryList test = new CategoryList(
    Primitives.ConstantPrimitives.ConnectionString, 
    Primitives.ConstantPrimitives.negativeShort, 
    false);
Assert.AreEqual(test.Cat_ID, null);