这一定是一个简单的菜鸟错误，但是

    def hi = hudson.model.Hudson.instance
   hi.getItems(hudson.model.Project).each {project ->
   println(project.displayName)
   def di = project.getDownstreamProjects

   println(di.name)

}

刚回来

groovy.lang.MissingPropertyException: No such property: getDownstreamProjects for class: hudson.model.FreeStyleProject

但是医生说该方法存在于AbstractProject上，我该怎么办？