anchor.diff:                      | body -> body.WriteAsync(buffer, offset, count, cancel)
   
           [<Extension>]
  -        static member inline WriteAsync (environment, (text:string), (encoding:Encoding), cancel) =
  +        static member WriteAsync (environment, text:string, encoding:Encoding, cancel) =
               if environment = null then invalidArg "environment" "environment is required"
               if text = null then invalidArg "text" "text is required"
               if encoding = null then invalidArg "encoding" "encoding is required"
  
positive.code:             x.WriteAsync (environment, text, Encoding.UTF8, token)
  
          [<Extension>]
          static member inline SetStatusCode (environment:Environment) (statusCode:int) = 
              environment.[ResponseStatusCodeKey] <- statusCode
negative.code:                 | _ -> Task.FromResult form
  
          [<Extension>]
          static member WriteAsync (environment, buffer, offset, count, cancel:CancellationToken) =
              if environment = null then invalidArg "environment" "environment is required"
              if buffer = null then invalidArg "buffer" "buffer is required"
  
  