restsharp/RestSharp — pull request #301 by Haacked (2012-07-18 16:27:02+00:00)
Title: Avoid potential NullReferenceException

If someone sets `BaseUrl` to null, it shouldn't throw a `NullReferenceException`. Either it's an `InvalidOperationException` or it should just set the value to null and not complain.

I took the latter approach.