I'm just starting out on this, and if I get an unproven ensures. That's fine IF I know what the contracts are on the methods I'm calling, if I don't know the contracts I'm guessing.
BUT, even though this would seem to be a large point about the contracts, can I find them anywhere? no.
e.g. what is the contract on IDictionary.Add?
I've read the Microsoft official docs and trawled the internet, I expected them to turn up in intellisense, I'll go and have a look at the object browser.
Install the Code Contracts Editor Extensions from Microsoft Research to get intellisense support for code contracts.