anchor.diff:                                  return Some this
           }
   
  -    /// **Description**
  -    ///
  +    /// <summary>
       /// Streams a file to the client.
       ///
  -    /// The handler will respect any valid HTTP pre-conditions (e.g. `If-Match`, `If-Modified-Since`, etc.) and return the most appropriate response. If the optional parameters `eTag` and/or `lastModified` have been set, then it will also set the `ETag` and/or `Last-Modified` HTTP headers in the response.
  -    ///
  -    /// **Parameters**
  -    ///
  -    /// `enableRangeProcessing`: If enabled then the handler will respect the `Range` and `If-Range` HTTP headers of the request as well as set all necessary HTTP headers in the response to enable HTTP range processing.
  -    /// `filePath`: The absolute or relative path (to `ContentRoot`) of the file.
  -    /// `eTag`: An optional entity tag which identifies the exact version of the file.
  -    /// `lastModified`: An optional parameter denoting the last modified date time of the file.
  -    ///
  -    /// **Output**
  -    ///
  -    /// Task of `Some HttpContext` after writing to the body of the response.
  -    ///
  +    /// The handler will respect any valid HTTP pre-conditions (e.g. If-Match, If-Modified-Since, etc.) and return the most appropriate response. If the optional parameters eTag and/or lastModified have been set, then it will also set the ETag and/or Last-Modified HTTP headers in the response.
  +    /// </summary>
  +    /// <param name="enableRangeProcessing">If enabled then the handler will respect the Range and If-Range HTTP headers of the request as well as set all necessary HTTP headers in the response to enable HTTP range processing.</param>
  +    /// <param name="filePath">The absolute or relative path (to ContentRoot) of the file.</param>
  +    /// <param name="eTag">An optional entity tag which identifies the exact version of the file.</param>
  +    /// <param name="lastModified">An optional parameter denoting the last modified date time of the file.</param>
  +    /// <returns>Task of Some HttpContext after writing to the body of the response.</returns>
       member this.WriteFileStreamAsync (enableRangeProcessing : bool)
                                        (filePath              : string)
                                        (eTag                  : EntityTagHeaderValue option)
  
positive.code:                 return Some this
          }
  
      /// **Description**
      ///
      /// Streams data to the client.
      ///
      /// The handler will respect any valid HTTP pre-conditions (e.g. `If-Match`, `If-Modified-Since`, etc.) and return the most appropriate response. If the optional parameters `eTag` and/or `lastModified` have been set, then it will also set the `ETag` and/or `Last-Modified` HTTP headers in the response.
      ///
      /// **Parameters**
      ///
      /// `enableRangeProcessing`: If enabled then the handler will respect the `Range` and `If-Range` HTTP headers of the request as well as set all necessary HTTP headers in the response to enable HTTP range processing.
      /// `stream`: The stream to be send to the client.
      /// `eTag`: An optional entity tag which identifies the exact version of the data.
      /// `lastModified`: An optional parameter denoting the last modified date time of the data.
      ///
      /// **Output**
      ///
      /// Task of `Some HttpContext` after writing to the body of the response.
      ///
      member this.WriteStreamAsync (enableRangeProcessing : bool)
                                   (stream                : Stream)
                                   (eTag                  : EntityTagHeaderValue option)
  
negative.code:     fun (_ : HttpFunc) (ctx : HttpContext) ->
          ctx.WriteStreamAsync enableRangeProcessing stream eTag lastModified
  
  /// <summary>
  /// Streams a file to the client.
  ///
  /// The handler will respect any valid HTTP pre-conditions (e.g. If-Match, If-Modified-Since, etc.) and return the most appropriate response. If the optional parameters eTag and/or lastModified have been set, then it will also set the ETag and/or Last-Modified HTTP headers in the response.
  /// </summary>
  /// <param name="enableRangeProcessing">If enabled then the handler will respect the Range and If-Range HTTP headers of the request as well as set all necessary HTTP headers in the response to enable HTTP range processing.</param>
  /// <param name="filePath">The absolute or relative path (to ContentRoot) of the file.</param>
  /// <param name="eTag">An optional entity tag which identifies the exact version of the file.</param>
  /// <param name="lastModified">An optional parameter denoting the last modified date time of the file.</param>
  /// <param name="ctx"></param>
  /// <returns>A Giraffe <see cref="HttpHandler"/> function which can be composed into a bigger web application.</returns>
  let streamFile (enableRangeProcessing : bool)
                 (filePath              : string)
                 (eTag                  : EntityTagHeaderValue option)
  