docs: public void deleteInactiveContent() throws PatchingException {
          List<File> dirs = getInactiveHistory();
          if (!dirs.isEmpty()) {
              for (File dir : dirs) {
                  deleteDir(dir, ALL);
              }
          }
          dirs = getInactiveOverlays();
          if (!dirs.isEmpty()) {
              for (File dir : dirs) {
                  deleteDir(dir, ALL);
              }
          }
      }