anchor.diff:                  if d.ContainsKey k then
                       d.[k] <- v
                   else
  +                    // TODO : Return a better error message
  +                    //keyNotFound ""
                       raise <| System.Collections.Generic.KeyNotFoundException ()
   
           /// Removes the entry with the specified key from the Dictionary,
  
positive.code:             dictionary
          else
              // TODO : Add an error message which includes the key.
              raise <| System.Collections.Generic.KeyNotFoundException ()
  
      /// Updates the value of an entry (which has the specified key) in
  
negative.code:     /// Removes the entry with the specified key from the Dictionary.
      /// An exception is raised if the entry cannot be removed.
      let [<NoDynamicInvocation>] inline remove (k : 'Key) (dictionary : IDictionary<'Key, 'T>) =
          if dictionary.Remove k then
              dictionary
          else
              let msg = sprintf "Unable to remove the entry with the key '%O' from the dictionary." k
              raise <| exn msg
  
      /// Lookup an element in the Dictionary, raising KeyNotFoundException if
      /// the dictionary does not contain an element with the specified key.
  