title: Override CompareTo: What to do with null case?
body: <p>What should be returned in a <code>CompareTo</code> method when the given object is <code>null</code>?</p>
  
  <p>The <a href="http://msdn.microsoft.com/en-us/library/system.icomparable%28v=vs.110%29.aspx">MSDN Library</a> shows a example where <code>1</code> is returned. But I would have expected to throw an error because comparing to <code>null</code> is not possible.</p>
  
  <p>I expect different opinions to this answer. What could be a best practice approach?</p>