code: public void copyBootClasspathLibraries() throws IOException {
          BootClasspathLibraryOption[] bootClasspathLibraryOptions = subsystem
              .getOptions(BootClasspathLibraryOption.class);
          for (BootClasspathLibraryOption bootClasspathLibraryOption : bootClasspathLibraryOptions) {
              UrlReference libraryUrl = bootClasspathLibraryOption.getLibraryUrl();
              FileUtils.copyURLToFile(
                  new URL(libraryUrl.getURL()),
                  createUnique(libraryUrl.getURL(), new File(
                      karafHome + "/lib"), new String[] { "jar" }));
          }
      }
docs: Copy jars specified as BootClasspathLibraryOption in system
  to the karaf lib path to make them available in the boot classpath
  
  @throws IOException if copy fails