Supplier<Object> supplier = () -> longString;

        monitorTarget.append(buf, "longKey", supplier);
        assertTrue(buf.toString().startsWith("\"longKey\":\""));
        assertTrue(buf.toString().contains("aaaaaaaaaa"));
        assertEquals(10000 + "\"longKey\":\"\"".length(), buf.toString().length());
    }

    // Test append with Unicode characters
    @Test
    public void test_append_unicodeCharacters() {

  }

  private Heap heapForIndex(int i) {
    return isEvenLevel(i) ? minHeap : maxHeap;
  }

  private static final int EVEN_POWERS_OF_TWO = 0x55555555;
  private static final int ODD_POWERS_OF_TWO = 0xaaaaaaaa;

  @VisibleForTesting
  static boolean isEvenLevel(int index) {
    int oneBased = ~~(index + 1); // for GWT
    checkState(oneBased > 0, "negative index");

  }

  private Heap heapForIndex(int i) {
    return isEvenLevel(i) ? minHeap : maxHeap;
  }

  private static final int EVEN_POWERS_OF_TWO = 0x55555555;
  private static final int ODD_POWERS_OF_TWO = 0xaaaaaaaa;

  @VisibleForTesting
  static boolean isEvenLevel(int index) {
    int oneBased = ~~(index + 1); // for GWT
    checkState(oneBased > 0, "negative index");