How to use

delete

method

in

org.kohsuke.github.GHRef

public static void deleteUpdateBotBranch(GHRepository ghRepository, String branchName) throws IOException {
  if (branchName.startsWith("updatebot-")) {
    //delete as per https://github.com/kohsuke/github-api/pull/164#issuecomment-78391771
    //heads needed as per https://developer.github.com/v3/git/refs/#get-a-reference
    ghRepository.getRef("heads/" + branchName).delete();
    LOG.info("deleted branch " + branchName + " for " + ghRepository.getFullName());
  }
}

private void deleteBranch(Run<?, ?> build, Launcher launcher, final TaskListener listener) {
  if (!getDeleteOnMerge()) {
    return;
  }
  String branchName = pr.getHead().getRef();
  try {
    GHRepository repo = pr.getRepository();
    GHRef ref = repo.getRef("heads/" + branchName);
    ref.delete();
    listener.getLogger().println("Deleted branch " + branchName);
  } catch (IOException e) {
    listener.getLogger().println("Unable to delete branch " + branchName);
    e.printStackTrace(listener.getLogger());
  }
}