anchor.diff:  ----------------------------
   
    * A few words on the `SandboxBuilder` works:
  -    - The library is build on top of the [AppDomain Class][appdomain] which 
  +    - The library is built on top of the [AppDomain Class][appdomain] which 
         allows to [Run Partially Trusted Code in a Sandbox][sandbox]. The 
         `SandboxBuilder` is only allowed to execute code
         `(SecurityPermissionFlag.Execution)`, which is the minimum permission that
  
positive.code:       in the `AppDomain`.
      - **Unit tests**: As stated before, `Reflection` is not supported and because NUnit 
        uses this approach to execute the test, then it will not work either. This makes
        it really difficult to test code, specially because `Unsafe` types are 
        runtime and not compile time.
      - **F# Interactive (fsiAnyCpu.exe)**: As the computation expression is built on 
        top of the `AppDomain`, it will not be possible to use this library in
  
negative.code: The next example show how we try to get access to the current file directory,
  count the amount of files and add it to the final result. This action will try 
  to perform an `File IO` which is not allowed in the `sandbox`. Due to this, the
  whole function is evaluated to an `Unsafe` value, which contain the `Exception` 
  thrown at runtime: *)
  
  let addition' x y = sandbox{ 
    return (Directory.EnumerateFiles(".") |> Seq.length) + x + y }
  