code: function handleMultipartRequestBody(request) {
  
          var form = new multiparty.Form({ uploadDir: tools.config.parameters.file.temp_storage });
  
          return new Promise(function (fulfill, reject) {
              form.parse(request, function(err, fields, files) {
                  if(err) {
                      reject(err);
                      return;
                  }
                  fulfill({ fields: fields, files: files });
              });
          });
      }
docs: / downloading of multipart form request body with files