public Supplier<Boolean> apply(Supplier<Boolean> supplier) {
            return Suppliers.memoize(supplier);
          }
        };
    testSupplierThreadSafe(memoizer);
  }

  @J2ktIncompatible
  @GwtIncompatible // Thread
  private void testSupplierThreadSafe(Function<Supplier<Boolean>, Supplier<Boolean>> memoizer)
      throws Throwable {
    AtomicInteger count = new AtomicInteger(0);