docs: function exportProjectToFile(projectId, branchName, commitHash, withAssets, callback) {
              var parameters = {
                  command: CONSTANTS.SERVER_WORKER_REQUESTS.EXPORT_PROJECT_TO_FILE,
                  projectId: projectId,
                  branchName: branchName,
                  commitHash: commitHash,
                  withAssets: withAssets
              };
  
              logger.debug('exportProjectToFile, parameters', parameters);
              if (parameters.projectId && (parameters.branchName || commitHash)) {
                  storage.simpleRequest(parameters, function (err, result) {
                      if (err && !result) {
                          logger.error('exportProjectToFile failed with error', err);
                          callback(err);
                      } else {
                          callback(err, result);
                      }
                  });
              } else {
                  callback(new Error('invalid parameters!'));
              }
          }