* @param envSupplier The environment supplier.
     * @return The directory context holder.
     */
    protected DirContextHolder getDirContext(final Supplier<Hashtable<String, String>> envSupplier) {
        DirContextHolder holder = contextLocal.get();
        if (holder != null) {
            holder.inc();
            return holder;
        }
        final Hashtable<String, String> env = envSupplier.get();

  }

  @Keep
  private static class Holder<T> {
    List<T>[] matrix;

    void setList(List<T> list) {}
  }

  public void testWildcardCaptured_methodParameter_upperBound() throws Exception {
    TypeToken<Holder<?>> type = new TypeToken<Holder<?>>() {};
    ImmutableList<Parameter> parameters =
        type.method(Holder.class.getDeclaredMethod("setList", List.class)).getParameters();

  }

  @Keep
  private static class Holder<T> {
    List<T>[] matrix;

    void setList(List<T> list) {}
  }

  public void testWildcardCaptured_methodParameter_upperBound() throws Exception {
    TypeToken<Holder<?>> type = new TypeToken<Holder<?>>() {};
    ImmutableList<Parameter> parameters =
        type.method(Holder.class.getDeclaredMethod("setList", List.class)).getParameters();

      return 1;
    }
  }

  static final Ticker NULL_TICKER =
      new Ticker() {
        @Override
        public long read() {
          return 0;
        }
      };

  // We use a holder class to delay initialization: https://github.com/google/guava/issues/6566
  private static final class LoggerHolder {
    static final Logger logger = Logger.getLogger(CacheBuilder.class.getName());
  }