code: function registerUserTasks() {
      var tasks  = options.tasks,
          task   = that.task.bind(that),
          before = that.before.bind(that),
          after  = that.after.bind(that),
          taskName;
  
      // register user tasks
      for (taskName in tasks) {
        if ( tasks.hasOwnProperty(taskName) ) {
          task(taskName, tasks[taskName]);
        }
      }
  
      // register predefined user tasks order
      before('deploy', 'beforeDeploy');
  
      before('updateCode', 'beforeUpdateCode');
      after('updateCode', 'afterUpdateCode');
  
      before('npm', 'beforeNpm');
      after('npm', 'afterNpm');
  
      before('createSymlink', 'beforeCreateSymlink');
      after('createSymlink', 'afterCreateSymlink');
  
      before('restart', 'beforeRestart');
      after('restart', 'afterRestart');
  
      after('deploy', 'afterDeploy');
    }
docs: Register user-callbacks defined tasks