适当的断言消息

在一个测试中，我试图断言两个TextSpan列表的相等性/等价性，如下所示:

var expectedSpans = new List<TextSpan>()
    {
     new TextSpan { iStartLine = 1, iEndLine = 1, iStartIndex = 1, iEndIndex = 1}
    };
var obtainedSpans = new List<TextSpan>()
    {
     new TextSpan { iStartLine = 2, iEndLine = 2, iStartIndex = 1, iEndIndex = 1}
    };
Assert.That(obtainedSpans, Is.EqualTo(expectedSpans), "Unexpected spans found");

我得到的信息是:

Expected tags were not obtained.
  Expected is <System.Collections.Generic.List`1[Microsoft.VisualStudio.TextManager.Interop.TextSpan]> with 1 elements, actual is <System.Collections.Generic.List`1[Microsoft.VisualStudio.TextManager.Interop.TextSpan]> with 1 elements
  Values differ at index [0]
  Expected: Microsoft.VisualStudio.TextManager.Interop.TextSpan
  But was:  Microsoft.VisualStudio.TextManager.Interop.TextSpan

我怎样才能得到更详细的消息，至少显示所有的值，让我弄清楚在哪里失去了相等/等价?在等价断言的情况下，该消息也不提供信息。