code: public JenkinsServer createJob(FolderJob folder, String jobName, String jobXml, Boolean crumbFlag)
              throws IOException {
          client.post_xml(UrlUtils.toBaseUrl(folder) + "createItem?name=" + EncodingUtils.formParameter(jobName), jobXml, crumbFlag);
          return this;
      }
docs: Create a job on the server using the provided xml and in the provided
  folder
  
  @param folder {@link FolderJob}
  @param jobName name of the job to be created.
  @param jobXml the <code>config.xml</code> which should be used to create
  the job.
  @param crumbFlag <code>true</code> to add <b>crumbIssuer</b>
  <code>false</code> otherwise.
  @throws IOException in case of an error.