docs: public static boolean pullImage(Launcher launcher, final String imageTag, final String username, final String password, final String host)
              throws IOException, InterruptedException {
  
          return launcher.getChannel().call(new MasterToSlaveCallable<Boolean, IOException>() {
              public Boolean call() throws IOException {
                  DockerUtils.pullImage(imageTag, username, password, host);
                  return true;
              }
          });
      }