/** Posts a note to set the expectation. */
  protected void greet(GHPullRequest pr) throws IOException {
    if (hasGreetingComment(pr)) return; // no need to do anything

    System.out.println("Greeting " + pr.getRepository().getName() + "\t" + pr.getTitle());

    pr.comment(
        String.format(
            "Thank you for a pull request! Please check [this document](%s) for how the Jenkins project handles pull requests",
            LINK));
  }
  void handle(GHEventPayload.IssueComment issueComment, GitHub gitHub) throws IOException {
    // check the trigger phrase
    PullRequestBuildTrigger trigger = project.getTrigger(PullRequestBuildTrigger.class);
    if (StringUtils.isBlank(trigger.getTriggerPhrase())) {
      if (LOGGER.isLoggable(Level.FINE)) {
        LOGGER.fine("No trigger phrase configured for project: " + project.getDisplayName());
      }
      return;
    }

    String issueUrl = issueComment.getIssue().getHtmlUrl().toString();
    if (!issueUrl.startsWith(gitHubRepositoryUrl)) {
      LOGGER.finest(
          MessageFormat.format(
              "GitHub issue {0} is not related to project {1}. "
                  + "GitHub project URL configured for project {1}: {2}",
              issueUrl, project.getFullName(), gitHubRepositoryUrl));

      return;
    }

    String commentBody = issueComment.getComment().getBody();
    if (!triggerPhrasePattern.matcher(commentBody).find()) {
      if (LOGGER.isLoggable(Level.FINE)) {
        LOGGER.fine("No trigger phrase matching on comment: " + commentBody);
      }
      return;
    }

    GHUser buildRequester = issueComment.getComment().getUser();
    if (!isWhitelisted(buildRequester, gitHub)) {
      LOGGER.info(
          MessageFormat.format(
              "GitHub user {0} is not in the whitelist of project {1}",
              buildRequester.getLogin(), project.getFullName()));

      return;
    }

    final int prNumber = issueComment.getIssue().getNumber();

    GHPullRequest pullRequest = issueComment.getRepository().getPullRequest(prNumber);
    // Updating PR to force the cache (if present) to refresh:
    pullRequest.setTitle(pullRequest.getTitle());

    pullRequest = issueComment.getRepository().getPullRequest(prNumber);

    if (LOGGER.isLoggable(Level.FINE)) {
      LOGGER.fine("ghPullRequest = " + getPullRequestAsString(pullRequest));
    }

    if (pullRequest.getState() == GHIssueState.OPEN) {
      PullRequestData pullRequestData =
          PullRequestManager.getInstance().addPullRequestData(pullRequest, project);

      cancelBuilds(pullRequestData);
      build(pullRequest, buildRequester, new TriggerCause(pullRequest, buildRequester));
    } else if (LOGGER.isLoggable(Level.FINE)) {
      LOGGER.fine(
          MessageFormat.format(
              "Pull request {0} is not opened, no build is triggered",
              pullRequest.getHtmlUrl().toString()));
    }
  }