code: @Override
      public void shutdown() {
          Throwable shutdownException = null;
          try {
              fire(new ManagerStopping());
          } catch (Exception e) {
              try {
                  fireException(e);
              } catch (Exception e2) {
                  shutdownException = e2;
              }
          }
          synchronized (this) {
              for (Context context : contexts) {
                  context.clearAll();
              }
              contexts.clear();
              extensions.clear();
  
              runtimeLogger.clear();
  
              handledThrowables.remove();
          }
          if (shutdownException != null) {
              UncheckedThrow.throwUnchecked(shutdownException);
          }
      }
docs: /* (non-Javadoc)
  @see org.jboss.arquillian.core.spi.Manager#shutdown()