code: public RunT loadBuild(File dir) throws IOException {
          try {
              return getBuildClass().getConstructor(asJob().getClass(), File.class).newInstance(asJob(), dir);
          } catch (InstantiationException | NoSuchMethodException | IllegalAccessException e) {
              throw new Error(e);
          } catch (InvocationTargetException e) {
              throw handleInvocationTargetException(e);
          }
      }
docs: Loads an existing build record from disk.
  The default implementation just calls the ({@link Job}, {@link File}) constructor of {@link #getBuildClass}.