code: function decompressorFor(response) {
      var contentEncoding = response.headers['content-encoding'];
      switch (contentEncoding) {
          case 'x-gzip':
          case 'gzip':
              return zlib.createGunzip();
          case 'deflate':
              return zlib.createInflate();
          default:
              return null;
      }
  }
docs: Get a stream transform to decompress an HTTP response (or null, if none required).
  
  NOTE: Does not handle 'compress', but in practice no-one has used that since the 90's.
  
  @param {http.ServerResponse} response - The server response to get a decompressor for.
  @returns {*} - A stream.Transform, or null if no decompression required.