Clear Jenkins Sandbox Folder from jobs

clearSandbox.groovy

import hudson.model.*

def isFolder = { it.class.canonicalName == 'com.cloudbees.hudson.plugins.folder.Folder' }
def isSandbox = { "sandbox" == it.fullName }

def deleteChildren = {
    it.getItems().collect { item ->
        def deletedName = item.fullName
        item.delete()
        "${deletedName} deleted"
    }
}

def findAndClearSandbox = { allJobs ->
   ["\nJobs found and removed in sandbox",
   "==================================",
    allJobs.findAll(isFolder)
      .findAll(isSandbox)
      .collect(deleteChildren)
      .flatten()
      .join('\n') ?: 'Nobody has been using the sandbox this week. :(',
    "=================================="].join('\n')
}

findAndClearSandbox(Hudson.instance.items)