new ContentWrapperAttribute(null).GetHashCode() throws NRE

[hughbe]

[Fact]
public void GetHashCode_NullContentWrapper_ThrowsNullReferenceException()
{
    var attribute = new ContentWrapperAttribute(null);
    Assert.Throws<NullReferenceException>(() => attribute.GetHashCode());
}

From https://blogs.msdn.microsoft.com/ericlippert/2011/02/28/guidelines-and-rules-for-gethashcode/:

Rule: GetHashCode must never throw an exception, and must return

Getting a hash code simply calculates an integer; there's no reason why it should ever fail. An implementation of GetHashCode should be able to handle any legal configuration of the object.