doTestEmpty(noneOf("CharMatcher"));
    doTestEmpty(inRange('n', 'q'));
    doTestEmpty(forPredicate(Predicates.equalTo('c')));
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNull() throws Exception {
    doTestNull(CharMatcher.any());
    doTestNull(CharMatcher.none());
    doTestNull(is('a'));
    doTestNull(isNot('a'));
    doTestNull(anyOf(""));
    doTestNull(anyOf("x"));

	TESTW R11, R11                          // 664585db
	TESTL $4045620583, (BX)                 // f703674523f1
	TESTL $4045620583, (R11)                // 41f703674523f1
	TESTL $4045620583, DX                   // f7c2674523f1
	TESTL $4045620583, R11                  // 41f7c3674523f1
	TESTL DX, (BX)                          // 8513
	TESTL R11, (BX)                         // 44851b
	TESTL DX, (R11)                         // 418513

	// create xlStorage test setup
	storage, path, err := newXLStorageTestSetup(t)
	if err != nil {
		t.Fatalf("Unable to create xlStorage test setup, %s", err)
	}

	volName := "testvol"
	fileName := "testfile"
	if err := storage.MakeVol(context.Background(), volName); err != nil {
		t.Fatal(err)
	}

	// 1) Whole-file bitrot check on proper file

</p>

<pre>
// uint64 atomicload64(uint64 volatile* addr);
// so actually
// void atomicload64(uint64 *res, uint64 volatile *addr);
TEXT runtime·atomicload64(SB), NOSPLIT, $0-12
	MOVL	ptr+0(FP), AX
	TESTL	$7, AX
	JZ	2(PC)
	MOVL	0, AX // crash with nil ptr deref
	LEAL	ret_lo+4(FP), BX
	// MOVQ (%EAX), %MM0
	BYTE $0x0f; BYTE $0x6f; BYTE $0x00
	// MOVQ %MM0, 0(%EBX)
	BYTE $0x0f; BYTE $0x7f; BYTE $0x03