t.start();
    }
    for (Thread t : threads) {
      t.join();
    }

    assertEquals(numThreads * iterations + 1, (int) nonThreadSafe.get());
  }

  public void testSupplierFunction() {
    Supplier<Integer> supplier = Suppliers.ofInstance(14);
    Function<Supplier<Integer>, Integer> supplierFunction = Suppliers.supplierFunction();

    assertEquals(14, (int) supplierFunction.apply(supplier));