List failing branches of failing builds in a Jenkins Pipeline

listFailedBranches.groovy

jobs = Jenkins.instance.allItems(hudson.model.Job).findAll { it.fullName == ("<JOBNAME>") }
jobs.each { job ->
  job.builds.findAll { !it.building }.each { build ->
    finished = new Date(build.timestamp.timeInMillis + build.duration)
    println "${build} - ${build.result} (${finished})"
    action = build.getAction(org.jenkinsci.plugins.workflow.job.views.FlowGraphAction)
    action.getNodes().findAll { it.displayName.startsWith("") }.each {
    if (it.displayName.startsWith("Building") && it.getError() != null) {
      println "\t${it.displayName}"
    }
   }
  }
}